Merge changes I5fad5161,I7ce390ca,Ib0b4ea11,I6cc72e13,Ic4a66b2c, ...

* changes:
  Re-log bta/gatt::bta_gattc_conn_cback
  Re-include btif/src/btif_sock_l2cap
  Eliminate socket verbosity print_events()
  Re-log stack/acl::BTM_SwitchRole
  Reduce identical APIs
  Remove #def code conditional BTM_MAX_SCO_LINKS
  Remove unused #defs stack/btm/btm_ble_int_types::
  Internally link stack/btm/btm_ble_gap::btm_send_hci_scan_enable
  Use new APIS stack/acl/btm_acl
  Streamline stack/acl/btm_acl::btm_acl_created
  Add new APIS stack/acl/btm_acl