Merge "Add/fix null-check on ringtoneSupplier." into udc-dev am: 29528d51

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/22290825



Change-Id: I8fb4462dc9e5bbb51fba6e844112e73fa6fa0e5c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>