Merge "Support CarrierConfigChangeListener in CarrierConfigLoader" am: 81588997c0 am: 89296acc50

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/2466903

Change-Id: I0adfede8368c9200213fba60e7fe6654a70f63cd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>