eSCO: Additional fix to get eSCO working for HFP and HSP (3/5)

* Removed vendor specific call after codec negotiation and before eSCO
  command is sent to Bluetooth chip
* Removed vendor specific call after a SCO connection is requested by
  the peer
* Removed vendor specific save audio state methods

Bug: 19540029
Test: make, HFP PTS test, testplans/86884, testplans/87103
Change-Id: I899405a8eaa2f38ee0de04949c5288f9eefa74df