[automerger skipped] [DO NOT MERGE] Make GlobalScreenshot PendingIntents...

[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

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

Change-Id: I7286da0ca4f2ee2b09a0b1daf7dd35291d699b25