Merge "Fix NPE in PipTaskOrganizer#setPipVisible" into udc-dev am: 29668d51 am: bf5d00ce

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



Change-Id: Ie24a9f1d0fe3fb468fd1d212dbdee27590848d57
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>