Do SDP when HSP connection starts by remote

Test: 1. Enable only HSP profile on AG.
2. Connect to AG from BT headset supporting HSP profile only with VGS
3. VOIP call (eg. skype, hangout)
4. Control the volume using AG volume keys.

Failure:
Volume changes are not taking affect.

Rootcause:
When remote is doing SDP first, HSP AG is skipping SDP.
As a result, AG is not aware if remote supports remote
volume control feature.

Fix:
Don't skip SDP when remote does SDP first. Do SDP always
so that AG could find out if remote supports remote volume
control feature.

Fixes: 35657384

Change-Id: I73707f774dc4ec53cbd510ded15f28f87659eec3