Merge "IMMS: Make IMMS PendingIntents immutable" into qt-dev am: 5ccf55eb am: 6c68f501

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19119301



Change-Id: I0d1cc16c84d5909e32efacfff3605cafbd9dc990
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>