Add CTS game mode frame rate override tests

FPS throttling intervention changes the frame rate
override API behavior. Corresponding tests are required.

- Create test cases against all frame rate observers
- Make FrameRateOverrideBehavior an interface
  and have GameMode, Surface two implementations
- Make test package a "game app" for game mode frame rate
  override by adding game category in AndriodManifest.xml

Bug: b/204322816, b/206128693
Test: atest FrameRateOverrideHostTest
Change-Id: I1b27b1b845aef599cae7c7246192189da338bd1c
4 files changed