Add demux to mFrontendTests am: 86aa7010 am: 6afaf8d1 am: 123934b0 am:...

Add demux to mFrontendTests am: 86aa7010 am: 6afaf8d1 am: 123934b0 am: 71be20f9 am: aa02c517 am: d50f545e

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2886926



Change-Id: I1a679e3fac591075c31fb9a636b756ae3aa0a0e8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>