Merge changes Ib81960bb,I1d84f463,Id475e310,I4ba9755c,Ib6f7b4ba, ...

* changes:
  Introduce main_shim_test
  Add main/test::shim mocks
  Add gd/neighbor::inquiry mock
  Add SCO HACK for shim acl mock
  Add gd/hci::controller mock
  gd_acl: Directly access acl manager for SCO hack
  Put stack vars in proper scope
  Return proper type stack/acl/btm_pm::BTM_SetPowerMode
  Explicitly specify status type include/hardware/ble_scanner.h
  Add stack init indirection for activity_attribution
  Use proper tBTM_STATUS types
  Use tBTM_STATUS in stack/l2cap/::
  gd_shim: Log more info about acl queue state
  Add bta_sys post to main alternative method
  Remove unused field srvc_id
  Template prep for bta hardening
  Use btm_status in stack/rfcomm/::
  Use proper types tBLE_SCAN_MODE
  User proper types tBTM_STATUS
  Canonicalize tBTM_APPL_INFO::bta_security
  Streamline bta_av_link_role_ok
  Use canonical include paths
  Add hci code conversion stack/include/hci_error_code
  Remove unused bta/include/bta_api::#defs
  Remove unused API BTM_GetPeerSCA
  Remove unused API BTM_RequestPeerSCA
  Remove unused API BTM_IsPhy2mSupported
  Properly conform tACL_CONN field names
  Add stack/include::BT_HDR rigid struct
  Use proper types tSMP_STATUS
  Properly type stack/smp::tSMP_EVT
  Remove useless extern keyword for definitions
  Remove unused stack/gatt/gatt_int::#defs
  Re-include bta/ag/bta_ag_sdp.cc