Merge "[User Switcher] Fix username sync in bouncer." into tm-qpr-dev am: 6a5411f6 am: b5d7a255

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20388389



Change-Id: I5848484a2a788053f64ee7d8ff224df951114ee2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>