Add APIs for ImsService RCS UCE implementation

Includes APIs for RCS User Capability Echange,
including presence and SIP OPTIONS.

Note: This CL only defines the API changes
needed for this, not the telephony implementation
to unblock vendor implementation and testing.

Test: Manual
Bug: 111305845
Change-Id: I91227a05cb7062f17aac78657e25e28fac2b4d5d