Ensure service unbind when receiving a null call screening service in onBind. am: 14927c6f0b am: a005a8529a am: 3d3098da90 am: 4451efa59e am: 12809100b6

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/21224930

Change-Id: Id3e65ddc6d5c7ad1cf4ff2b0b9d23bd24cb072a6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>