android: Android activity lifecycle callbacks
This MR is based on !722 and reuse some of those interfaces definition. The goal is to translate Android activity lifecycle event to corresponding session state events. Without this changes, app will keep rendering even it goes to background (onPause
state) in out-of-process build with display over other apps enabled.
Tested with hello_xr on Pixel 4 (Android 13)/Moto Edge 5G (Android 12).