IMS-VT: Fix one-way to bidirectional video upgrades

Requests to upgrade current one-way video
call to bidirectional video are ignored since
the consent options are not presented to the user.
This change ensures that the consent options are
presented to the user for any upgrade request.

BUG=29007241
Change-Id: Ib940d335176d5f2a1ed8e98fdf012058ecc6ca12