[Android] Fix gradle and plugin versions with Android Studio 3.0 Canary 6

android/build.gradle

         maven { url 'https://maven.google.com' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0-alpha4'
+        classpath 'com.android.tools.build:gradle:3.0.0-alpha6'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files.

android/gradle/wrapper/gradle-wrapper.properties

+#Mon Jul 17 18:25:08 CEST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.0-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-milestone-1-all.zip