[automerger skipped] Merge "Add immutability flag to PendingIntents" into rvc-qpr-dev am: 5a2b08a5 -s ours

am skip reason: skip tag Change-Id Iae1489b9c8fa323448e60615e99ad96aee1cd1d7 with SHA-1 281d1502 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13690445

Change-Id: I18bf8923c2c54554bb0e6dde3564a53eaab47f5d