tree 322fe771054c4f5e111b6c31ab7a0778e636b9b4
parent dbda8935a3bfc943ffc72772db6a8ac499234616
author Deqiang Chen <deqiangc@google.com> 1561154527 -0700
committer deqiang chen <deqiangc@google.com> 1563489832 -0700

Support vendor AT command and response for Hfp Client in bt stack

Add necessary interface in system/bt to support sending vendor AT
command. Also passing unknow events(vendor specific events) up for
further processing.

Bug: 132813146

Test: local test with kichensink to send vendor at command and receive
response. Also run unit test
atest BluetoothHeadsetClientStateMachineTest

Change-Id: Id460eaf00be269d15e6baf0fd30bdbf8e57df78d