Floss: Implement Pandora HFP profile (part1).

Bug: 300954040
Bug: 301036159
Bug: 300954041
Bug: 300954043
Bug: 300954042
Bug: 300942872
Bug: 300942873
Bug: 301000128
Bug: 300954044
Bug: 301000132
Bug: 301000135

Test: mma packages/modules/Bluetooth && pts-bot HFP
Tag: #floss
Flag: EXEMPT floss only changes
Change-Id: I76df131eeb6ccd18d8a2e5b324f76af571c6e805