title: could not run any code after flutter_upgrade
body: <p>after i upgrade my flutter, i can't run any code. even the sample code throw exception and don't run.
  i search some, but i can't resolve this problem.</p>
  <pre><code>FAILURE: Build failed with an exception.
  
  * What went wrong:
  Could not determine the dependencies of task ':app:compileDebugJavaWithJavac'.
  &gt; Could not resolve all task dependencies for configuration ':app:debugCompileClasspath'.
     &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
       Required by:
           project :app
        &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://dl.google.com/dl/android/maven2/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://dl.google.com/dl/android/maven2/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://jcenter.bintray.com/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://jcenter.bintray.com/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:flutter_embedding_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/flutter_embedding_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/flutter_embedding_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
     &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
       Required by:
           project :app
        &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://dl.google.com/dl/android/maven2/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://dl.google.com/dl/android/maven2/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://jcenter.bintray.com/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://jcenter.bintray.com/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
     &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
       Required by:
           project :app
        &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://dl.google.com/dl/android/maven2/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://dl.google.com/dl/android/maven2/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://jcenter.bintray.com/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://jcenter.bintray.com/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
        &gt; Could not resolve io.flutter:x86_64_debug:1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.
           &gt; Could not get resource 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
              &gt; Could not GET 'https://storage.googleapis.com/download.flutter.io/io/flutter/x86_64_debug/1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95/x86_64_debug-1.0.0-9d5b21729ff53dbf8eadd8bc97e0e30d77abec95.pom'.
                 &gt; Connect to mirror.vtwo.org:8850 [mirror.vtwo.org/5.152.221.178] failed: Connection timed out: connect
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
  
  * Get more help at https://help.gradle.org
  
  BUILD FAILED in 11m 2s
  Exception: Gradle task assembleDebug failed with exit code 1
  </code></pre>
  <p>and this is my flutter doctor</p>
  <blockquote>
  <p>Doctor summary (to see all details, run flutter doctor -v): [√]
  Flutter (Channel stable, 1.20.2, on Microsoft Windows [Version
  10.0.18362.1016], locale en-US)</p>
  <p>[√] Android toolchain - develop for Android devices (Android SDK
  version 29.0.3) [√] Android Studio (version 3.5) [√] VS Code (version
  1.47.2) [√] Connected device (1 available)</p>
  <p>• No issues found!</p>
  </blockquote>
  <p>thank's a lot for your answers</p>
  <p><strong>UPDATE:
  I update the Gradle and the problem is solving</strong></p>