Merge "Fix NPE in PipTaskOrganizer#setPipVisible" into udc-dev am: 29668d51

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23665533



Change-Id: I861e9faa1f4f6d3fee99399e99f267761ed40346
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>