Merge "Only update the compat system UI visibility if the source is valid"...

Merge "Only update the compat system UI visibility if the source is valid" into tm-dev am: 1fab4540 am: c19f57ce am: a15b3dd8 am: ecc02bf3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18583184



Change-Id: I9509af187d242ee52272fb9880ed7803a0c79a6a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>