Ensure service unbind when receiving a null call screening service in onBind. am: 14927c6f0b am: a005a8529a am: 3d3098da90 am: 4451efa59e am: 12809100b6 am: 4854fd48ab am: 186e7f6349 am: 2b64ad7e46

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

Change-Id: Ibe0b6a46dd5ddc6c2b58afacbc4ae70338f29e5e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>