From the code provided, most of the errors are due to failing to define entityR.
This doesn't appear to be standard LGL and looks custom.
APP_ABI := arm64-v8a armeabi-v7a, should be on or the other.
APP_PLATFORM := android-21, unless necessary this is usually blank for default.
Beyond that, your best bet would be @Poison Modz as he is our resident Menu code expert.