Merge "Exclude MediaSession2 from the media button session" into rvc-dev am: 31fdc74154 am: 458d37d5bb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12042284

Change-Id: Ia3455b26a3fbf3fabf67240c92de5410ddd64671