Android - Add proguard automatically into aar library https://plus.google.com/+IanLake/posts/1HfDuFFkMXG
android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defaultConfig {
minSdkVersion 15
targetSdkVersion 22
versionCode libVersionCode
versionName libVersionName
consumerProguardFiles 'proguard-rules.txt'
}
}