Merge "Optimize mirror layer management" into sc-dev am: a1f13f4c3c am: c419b42431

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/15180135

Change-Id: I6a9da1d0b81a6e5eeadfb187c71c915d3bb08a20