audio: Use hardcoded r_submix configuration with XML am: fc35ca3d32 am: 067d106779 am: 9d6f832b8e

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

Change-Id: I51a84be684a0a450947b28fdd9ebed2a74b31ac7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>