ScreenDecorations: Fix stuck / delayed rotations

Fixes the issue of stuck or delayed decor overlay rotations. The current logic
cannot handle the case where the overlay has not finished rotating when we start
another rotation.

To work around that, we make sure that the rotation finishes fast enough for that
not to happen, by decoupling it from the rest of SystemUI's traversals on a dedicated
thread.

Also fixes an issue in ScreenDecorations where we restarted drawing even though that
was not needed, which further delayed finishing the rotation of the overlay.

Also fixes an issue in ScreenDecorations where a spurious traversal after rotation
started but before SysUI was notified could draw in the wrong orientation. To prevent
that, we validate that our rotation matches the display rotation and restart the draw
otherwise.

In the future, we should investigate whether we can make this more robust by allowing
stacked rotations, or forbidding rotations while the overlay is not done yet. We should
also make the synchronization between WM and SysUI on what rotation is being drawn more
explict and thus more robust.

Change-Id: I5303a6a8e6392d309c0fe672ff6d1386ae18f235
Merged-In: I5303a6a8e6392d309c0fe672ff6d1386ae18f235
Bug: 111761727
Test: Ensure you have a lot of notifications, and enable cutout emulation, open camera, quickly rotate phone between landscape and portrait repeatedly, ensure there are no artifacts on screen.
Test: atest ScreenDecorationsTest