Create Conferences with a call direction set

Instead of always using UNDEFINED, create conferences with the
direction sent for IMS multiparty conference hosts.

This allows the call to be logged with the correct direction in
the call log.

Bug: 153595501
Fixes: 154246448
Test: atest TelecomUnitTests
Merged-In: I7621752f4f6fabeb1b17bac44c4e5e2795c7d052
Change-Id: I7621752f4f6fabeb1b17bac44c4e5e2795c7d052