Merge "Use MediaPlayer in a background thread." into tm-dev am: a7358c9d am: 5b34e393

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18723155



Change-Id: Ief6a4b8af43441d2ee7221aafe018e81cc366085
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>