Merge "Add a mutability flag to the PendingIntent" am: e80c5b3335

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1505734

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Idd6c05fbe1fee9c1e3858ef1d52da9dc8c8c7366