Merge changes I8fc751c7,Id99b76d8,I9c17bdfb,I8ecb755b,Iceebe867, ...

* changes:
  btm_acl_report_role_change does nothing, remove it
  p_switch_role_cb is never set to anything other than null
  callback param to BTM_SwitchRole is always null, remove it
  bta_dm_check_av is only called with 0
  bta_dm_check_av(BTA_DM_API_SEARCH_EVT) will never return true
  Remove BTA_DM_AVOID_A2DP_ROLESWITCH_ON_INQUIRY, it's always true
  Don't set link policy from btm_sec_connected