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: 1b0e2333 am: 47c49a72 am: dd438082

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



Change-Id: I40bb0c232d888eb68e5a9d44be6610620224e85b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>