Ensure video provider is set on ImsConference from host connection.

We were not previously setting the conference host on the conference from
the conference host connection.  This prevented control of a video
conference call.

Change-Id: I5cbaf70c17bbe38de90bda823148b736481c92f1
Test: Manual live carrier testing with custom build by build team.
Bug: 162470056
2 files changed