Merge "Support CarrierConfigChangeListener in CarrierConfigLoader" am: 81588997c0

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

Change-Id: I8e5063addd641959ab93ed0ccf98ded7f0340cbd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>