After upgrade message states:
Failed to refresh Gradle project \'XXX\' The project is using an unsupported version of the Android Gradle plug-in (0.8.3). Ve
Android Studio version 1.0.2 The idea of tight coupling between IDE version and build version is bad.
Android Studio 1.0.2. Gralde plugin 1.0.+ gradle.properties, distribution URL=http://services.gradle.org/distributions/gradle-2.2.1-bin.zip