Add TaskSurfaceHelper/Controller in WMShell to plumb game mode to SF

TaskSurfaceHelper(Controller) will be used as an interface to communicate
with the SurfaceControl of the underlying Task. This change adds a function
to set the game mode metadata for the task layer.

Bug: 186025682
Test: atest TaskSurfaceControllerTest
Change-Id: I136b65636b98e1883eaf9e4f4f0b34c61350d4e4
9 files changed