Merge "[Output Switcher] Add unmute function on volume icon" into udc-dev am: 528dfcfe

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22290782



Change-Id: I8f648a5f7e25986cc0576e4b8bfbb6c56d5cdecd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>