Scaffolding for SipTransport Impl & Implement SipTransport#isSupported

Creates a new SipTransportController class, which hooks into
TelephonyRcsService and will implement the SipDelegate
management.

SipDelegateManager#isSupported is implemented, which
ensures all of the following are true before returning
supported:
- ImsService#CAPABILITY_SIP_DELEGATE_CREATION is set on ImsService
- ImsService returns non-null implementation of SipTransportImplBase
- CarrierConfigManager.Ims.KEY_RCS_SINGLE_REGISTRATION_REQUIRED_BOOL is true

Bug: 154763999
Test: atest TeleServiceTests
Merged-In: I01677351c53b8c8480736f1a6539ece0bedf685f
Change-Id: I01677351c53b8c8480736f1a6539ece0bedf685f
8 files changed