Merge "[Output Switcher] Allow volume adjustment for Guest" into udc-dev am:...

Merge "[Output Switcher] Allow volume adjustment for Guest" into udc-dev am: 0a2ecf1c am: 3a1da8a4 am: 97e1ac78 am: b4a9b9f4

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23831003



Change-Id: I662609b74828c332b2e4c89b2b067b8822f0f1c7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>