Merge "Fix NPE in PipTaskOrganizer#setPipVisible" into udc-dev am: 29668d51 am: ad9fae9b am: 84555308 am: 1caabcf9

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



Change-Id: Iecf2cc636b578dd019b4b655d89a35da916354c0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>