Merge "Add null check for mRootTaskInfo in AppPair dump" am: e39da5a9a7 am: 6b88dadc8b am: 6eb2fbbe3c

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1890538

Change-Id: Ia911fe0f41a537f400b0c5de6713d5f4a6d4c9d7