Merge "Add global microphone mute key for keyboard" am: e85f271021

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2263102

Change-Id: Idf4643df3f011352ae07b1920ba2ded863ab7165
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>