I created a new project in Android Studio 2.2 Preview 1 with Android App and Backend module with Google Messaging. This is the app file: apply plugin: 'com.android.application' android { compileSdkVersion 23 buildToolsVersion "23.0.3" defaultConfig { applicationId "com.xxx.xxx" minSdkVersion 15 targetSdkVersion 23 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runn