log info to help tracing in notifyNewRingingConnectionP

The notifyNewRingingConnectionP(Connection) method has
been updated to help debug an incoming call better.
The phoneId, Connetion, and mNewRingingConnectionRegistrants
objects are now logged out (at info level) whenever there
is a new incoming call.

bug: 210480181
Test: none
Change-Id: Ie5114c1c1e0a10cb60667cad5f548d370d5c21d8