title: Failed to resolve: com.android.support:appcompat-v7:jar
body: <p>I am newbie in Android Studio Platform. I am getting this error 
  " Failed to resolve: com.android.support:appcompat-v7:jar "</p>
  
  <p>Currently my version Android Studio is 3.5.0.
  I Have added google() on build.gradle repositories</p>
  
  <p>This is my build.gradle (Project)</p>
  
  <pre><code>
  buildscript {
      repositories {
  
          jcenter()
      google()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.5.0'
          classpath 'com.google.gms:google-services:3.2.0'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  allprojects {
      repositories {
          jcenter()
      google()
  
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>This is my build.gradle (Module app)</p>
  
  <pre><code>apply plugin: 'com.google.gms.google-services'
  android {
      compileSdkVersion 28
      buildToolsVersion '28.0.3'
  
      defaultConfig {
          applicationId "com.kartik.barcode"
          minSdkVersion 17
          targetSdkVersion 23
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
      testImplementation 'junit:junit:4.12'
      implementation 'com.android.support:appcompat-v7:jar:28.0.0-alpha1'
      implementation 'com.android.support:support-v4:28.0.0'
      implementation 'com.android.support:support-media-compat:28.0.0'
      implementation 'com.android.support:animated-vector-drawable:28.0.0'
      implementation 'com.android.support:customtabs:28.0.0'
      //implementation 'com.android.support:design:jar:28.0.0-alpha1'
      implementation 'com.journeyapps:zxing-android-embedded:3.0.2@aar'
      implementation 'com.google.zxing:core:3.2.0'
     // implementation 'com.android.support:design:jar:28.0.0-alpha1'//for The edittext animation
      implementation 'com.google.firebase:firebase-database:9.0.0'//for firebase
      implementation 'com.google.firebase:firebase-auth:9.0.0'
      implementation 'com.google.firebase:firebase-storage:9.0.0'
      implementation 'com.google.android.gms:play-services-auth:9.0.0'
      implementation 'com.google.firebase:firebase-appindexing:19.0.0'
      implementation 'com.squareup.picasso:picasso:2.5.2'
  }
  </code></pre>
  
  <p>I am still getting this error:
  ERROR: Failed to resolve: com.android.support:appcompat-v7:jar
  Show in Project Structure dialog
  Affected Modules: app</p>