Merge "Updating SysUI state when back enabled/disabled state change" into...

Merge "Updating SysUI state when back enabled/disabled state change" into rvc-dev am: d71e76fd am: 58789f6c am: 1e01bb51

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11965840

Change-Id: I56b4c4632618bc43033bc38dcd42cdf435712f95