Common properties, excluding task bounds, will be migrated from
the bubble task to the root task, allowing them to inherit from
the parent.
The root task's bounds will now match the top-most bubble task.
This also allows other bubble tasks to be occluded by the top
bubble task if its override bounds are equal to its parent's.
Bug: 407669465
Test: BubbleControllerTest
Test: BubbleUtilsTest
Flag: com.android.window.flags.root_task_for_bubble
Change-Id: I7a0c5231c0e1c70e94dab69bb3ad04d5fc04929d