Refactor CountryDetectorServiceTest

-Modify notifyReceivers_twoListenersRegistered_bothNotified() to
 support immediate callback info to listeners based on ag/20470367

Bug: 262325136
Test: atest FrameworksServicesTests
Change-Id: I1f0b6f8244cbace325fde30c1fbad21aca44a710
1 file changed