HF: PTS Issue TC_HF_RSV_BV_01_I Fix

When volume changed from HF Device, it is unable to send volume change
intent from HeadsetClientservice to HesetClentStatemachine.So, AT command
regarding Volume changes will not be able to send to AG device.changed
streamType check from STREAM_VOICE_CALL to STREAM_BLUETOOTH_SCO.

CRs-Fixed: 1027595
Change-Id: Icbf501c304be1ae0d675d4f7926acff26f783ae2