HFP 1.7 profile update (1/4)

-> Added AG support for HFP 1.7 version upgrade which
   adds new type of indicator called HF(headset) indicators.
-> Added support for two new AT commands AT + BIND and AT + BIEV
   which have been appended to Hands-Free SLC sequence.
-> Added support to propagate the above commands and their data to
   the upper layers.

Bug: 19983867
Change-Id: I93d5b2af949f9fb99507a954e623cd0927ddc976
(cherry picked from commit e5bed64926d6ae45501617052f90932287da135b)