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 am: 7cfe5154

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

Change-Id: If428565e69e7eb50a7b4ca6891632e2c36fd6bdf