Support per user game config override

* Note that only supported game modes of a package are allowed to
  override through shell commands, while the resolution scaling APIs
  support all game modes at least until we have new game mode
  GAME_MODE_CUSTOM

Bug: b/240335717
Test: atest GameManagerServiceTests
Change-Id: Id145fe3a4af7f05812aa8fb3fd5d27be6211502c