There is a new Android Studio update: https://sites.google.com/a/android.com/tools/recent/androidstudio030released
The link says:
The improved per
The Android Studio ask you for download and install the Gradle version 1.8 for you.
Also the Android Gradle plugin version 0.6.2 has an issue and not works properly.
As said on the official page use the version 0.6.3:
dependencies {
classpath 'com.android.tools.build:gradle:0.6.3'
}
More info: http://tools.android.com/knownissues