[automerger skipped] [DO NOT MERGE] Make GlobalScreenshot PendingIntents immutable am: 44124798 am: 40297a24 am: 368eecbe -s ours am: b20d5c3a -s ours am: f69d6cfb am: 0bf1c91f -s ours am: 435a7cd8 am: ecf2db45 am: fa6aefea

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12773217

Change-Id: Ic255de229c9812ce8e752b847a73b3776e20fd72