Merge "Add FLAG_IMMUTABLE to PendingIntents" am: a3aa817aa5 am: b119c3792c am: fc609be986 am: 37b0cb3495 am: c597652305

Original change: https://android-review.googlesource.com/c/platform/development/+/2229375

Change-Id: I85d6e2d4503367a5bdcc166caaff6a7e82ea4f32
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>