Merge "Ignore null action in SliceManagerService." into main am: 06c052d9e7

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3319639

Change-Id: If456f8ec403b3f4c87114f39428452dabab641fe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>