Merge "Add unit test for CarrierConfigLoader" am: 98d9b75538 am: bdf781397f am: 3605fd1eb5

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/1668645

Change-Id: Ibbb51aba8282ddbac195824d7f6067d789ca5a48