Update output's dirty region when content changes

Correctly track content changes and update the output's dirty
region. The region is used to update the virtual display
contents. If the changes are not tracked, we may fail to update
the virtual display surface. Fix by tracking the content changes
at the layer as well as accounting for inherited parent layer
changes.

Flag: EXEMPT bugfix
Test: atest com.google.android.gts.cast.VirtualDisplayHostTest#testTestActivityEmbeddingOnVirtualDisplay  --rerun-until-failure
Bug: 360050020, 338403827
Change-Id: Iea4d8bbf0e5d478e908daafb10d13432d524da77