Merge "Merge "Mark implicit PendingIntents as immutable" into rvc-dev am:...

Merge "Merge "Mark implicit PendingIntents as immutable" into rvc-dev am: e35ad478 am: 205fd265 am: 94b589ba" into rvc-qpr-dev-plus-aosp am: 8633e4db

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12296407

Change-Id: I0e7dcda5f10679e464671eda2f81f6ef11815e86