Merge changes I169239c0,I7029221c,If1d05a00,I669acfed

* changes:
  Add stack/include/acl_api for LE parameter request
  Use new ACL API for btm_establish_continue
  Add stack/acl/btm_acl.cc::btm_establish_continue_from_address
  This is why we encapsulate stack/l2cap/l2c_ble.cc