I was able to decrease the size down to 46 MB by adding:
ndk {
abiFilters "armeabi-v7a"
}
like this (build.gradle):
buildTypes {
release {
ndk {
abiFilters "armeabi-v7a"
}
debuggable false
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
signingConfig signingConfigs.release
}
}