Merge "mediaserver: add more hwbinder threads" into rvc-dev am: 2038329c am: 90dcc0b7 am: 9cb6bd95

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/12046706

Change-Id: I26bb5ef962ea88021bccfa96a63f57ef053353c1