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: 3961746e am: cf4a59b6

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

Change-Id: I4246f0945d75b579bce2d25f1adf02b228529f37