Correct issue where conference calls were triggering anomalies.

Conference and their children (existing connections) do not undergo the
full "create connection complete" process like other connections do.
Therefore we can set the create connection complete attribute on the
associated calls to "true" right away.  This was an oversight in the
original implementation.

Test: Start conference call on device; verify that no anomaly and state
timeout takes place.
Fixes: 269920125

Change-Id: Ie99f7d8834bf68661904c7f3fae2b15484702847