Bluetooth: use virtual sco calls for VOIP

 - use virtualvoicesco connection set-up for VOIP calls
 - cannot simply revert c18c9138
and 25fc29b3 changes because
of aidl modifications involved.

Change-Id: Ib49cb01151a9cea2e94bc7a51ad1f58e877271aa
CRs-Fixed: 598072