Add TelephonyRegistryTest.

It's unit-test of TelephonyRegistry module. In first step it will
only have testPhoneCapabilityChanged, as it's new functionality
recently added. More tests will be added later.

Bug: 113305153
Test: unittest
Change-Id: I23648e164d4afdb682feb9ec6d8ca75097b550c3
Merged-In: I23648e164d4afdb682feb9ec6d8ca75097b550c3