Merge "Allow to register RENDER AudioMix pointing to previously registered...

Merge "Allow to register RENDER AudioMix pointing to previously registered LOOPBACK AudioMix." into udc-dev am: 55825ec1 am: 8a9bce9a am: 6b02cc62 am: 87fda223

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/23693534



Change-Id: Iaf0e1b71f21cb45bd591db77575db9874fa1192e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>