Fix leak due to PhoneConfigurationManager

1) Ensure the registrants in PhoneConfigurationManager are cleared after tests
to prevent memory leaks.
2) Convert CarrierAppUtilsTest to JUnit4 so it respects the @Ignore tag properly.

Bug: 155320231
Test: atest FrameworksTelephonyTests TeleServiceTest
Change-Id: I4cf7dca0b82c743a8132925dce0d3edd63659353