Merge "Remove root layer when clearing mLayersPendingRemoval" into tm-dev am: b089aa579f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/17837364

Change-Id: I43d447e703197dfffdbc8b2adc088d9398ddb723
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>