Implement new IMS system APIs

1) Implements new IMS system APIs
2) Moves FEATURE_TELEPHONY_IMS check here.

Bug: 122098288
Bug: 141457496
Test: atest FrameworksTelephonyTest
Merged-In: Iff8b1289a77abc438862f6d6136532b2e7c42fc8
Change-Id: Iff8b1289a77abc438862f6d6136532b2e7c42fc8
1 file changed