Remove callback upon MediaSession#release am: 3cfa79c53c am: b68a7b7822

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24464032

Change-Id: Idb0b10d11a681edbb05f08c3101bf7062b741043
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>