Merge "Revert "Fix user switcher flicker."" into udc-dev am: adf330a1a7

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24328794

Change-Id: I657ac5bc03207f8a407d99fea4cacd7e847ca056
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>