message: Correct response params in UnSubscribeVehicleData
  Corrected response parameters, generated in case when vi interface is not available.
  Related to:
diff: /*
  - Copyright (c) 2013, Ford Motor Company
  + Copyright (c) 2017, Ford Motor Company
  All rights reserved.
  Redistribution and use in source and binary forms, with or without
  @@ -201,16 +201,14 @@ void UnsubscribeVehicleDataRequest::Run() {
  }
  if (is_everything_already_unsubscribed) {
  - mobile_apis::Result::eType result_code =
  - vi_already_unsubscribed_by_this_app_.size()
  - ? mobile_apis::Result::IGNORED
  - : mobile_apis::Result::SUCCESS;
  -
  - const char* info = vi_already_unsubscribed_by_this_app_.size()
  - ? "Already subscribed on some provided VehicleData."
  - : NULL;
  -
  - SendResponse(true, result_code, info, &response_params);
  + if (!vi_already_unsubscribed_by_this_app_.empty()) {
  + SendResponse(false,
  + mobile_apis::Result::IGNORED,
  + "Some provided VehicleData was not subscribed.",
  + &response_params);
  + } else {
  + SendResponse(true, mobile_apis::Result::SUCCESS, NULL, &response_params);
  + }
  return;
  }
  