Merge "[Output Switcher] UI polish and A11y bug fix" into udc-dev am: 4adfb70d9a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23241359

Change-Id: Ie732412b3cf00b259e511cee334685d3f32740ac
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>