Merge "Audio r_submix : Handle the usecase when no data is available to read." into main am: 0bc307a5dd am: 830e95f8dd am: 731058e036

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2686486

Change-Id: I4df3aef456a7217fc6db6129ac48b2a02e4bbbbb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>