Bluetooth: Synchronize Virtual Call,Voice Call and A2dp

Found some IOT Issues were headsets behave abnormally if there is
START or SUSPEND over AVDTP in between call indicators sent for
Voip calls. This change will make sure A2dp is Suspended before
sending call indicators and Starts once the Virtual call is Ended.

Change-Id: Iaef6c08b593581112519e53a5d73086fd1539b99
CRs-fixed: 503739,516722
(cherry picked from commit 95f3b44bea38cf7219a88979275a40c57e26429c)
(cherry picked from commit adfb876ce4b81ece6a64c04565d4ad61649c05c7)
(cherry picked from commit 0b848e0765c4b999bec127fad13c651d437e6e56)