audio: Implement blocking in remote submix when there is no sink am: 6507376f

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/26684914



Change-Id: I6a4a1b6c0eab6808db990e3bc341e9945812a1b9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>