audio: Use hardcoded r_submix configuration with XML am: fc35ca3d32

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2794109

Change-Id: Ieebbe5fe8ca256a02979220bb3ea5b1419b36a76
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>