Merge "Call onDismissed on dismiss even mUserSwitchingDialog is null." into udc-dev am: 3cb27206 am: b1764868

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23289736



Change-Id: I590061e0825fb414b1091186793f2517af6decfe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>