I\'m about to upload my first app to the Google Play store and when I uploaded the APK to the Developer Console, it says under Localizations: default + 55 languages
At the time of apk build,aapt used to merge required folder(like res) specified into library that you required for your Application.
Like below code adds google play service usage in your app.
dependencies{
compile 'com.google.android.gms:play-services-base:8.3.0'
compile 'com.google.android.gms:play-services-gcm:8.3.0'
}
We can verify this by decompiling apk(using apktool),It shows values folders for supported languages by Your APP + added library.
In case you only want to show specific languages for your app,You can set it in argument as shown below in build.gradle file.
defaultConfig {
resConfigs "en", "en_US", "en_UK"
}
This significantly shrink apk size.