Merge "Make user switching dialog cover top part of the screen as well." into udc-dev am: 72e4b7e0 am: c919a7e4 am: 229b019e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23639284



Change-Id: I3d4f782bc173adeabc18e9916953477eb19f3e4a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>