title: Gradle - "enforceUniquePackageName" deprecated with version 3.0.0+?
body: <pre><code>android {
      enforceUniquePackageName = false
  }
  </code></pre>
  
  <p>"enforceUniquePackageName" works with the gradle version:</p>
  
  <pre><code>dependencies {
      classpath 'com.android.tools.build:gradle:2.3.1'
  }
  </code></pre>
  
  <p>However, if I change the gradle version to 3.0.0</p>
  
  <pre><code>dependencies {
      classpath 'com.android.tools.build:gradle:3.0.0-alpha9'
  }
  </code></pre>
  
  <p>I get: </p>
  
  <pre><code>Could not set unknown property 'enforceUniquePackageName' for object of type com.android.build.gradle.AppExtension. Open File
  </code></pre>
  
  <p>If 'enforceUniquePackageName' property is deprecated, then what would be the alternative option?</p>