Merge "Change Fullscreen UserSwitcher into a dialog" into tm-qpr-dev am: 4a429c46 am: 80cafa8c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22210083



Change-Id: I698218716b0f1c54df3237b317f60526fd164cf0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>