Merge "Fix null dereference in WMShell transition" into main am: 91dcf18eb0

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3220823

Change-Id: Ibe4987c990ca9ffe9210fd1f16f043e99ace87a4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>