Some fixes to TrustedPresentationListener

1. Ignore display overlays since we don't want screen decorations
   included in the occlusion

2. Handle occluded region as separate Rects to ensure that disconnected
   Rects in a Region are not considered occluding in the disconnected
   area.

Test: LayerTrustedPresentationListenerTest
Bug: 256993331
Change-Id: Ib0a4b850e2aafb42e206b8728fcc9b6013171f3f
8 files changed