[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

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

Change-Id: Iaf03009c5e15b54eb254d80e18394888905b83e4