message: fix: invalid memory access in Policy Manager when HMI level is invalid
diff: @@ -1527,6 +1527,13 @@ void PolicyHandler::CheckPermissions(
  POLICY_LIB_CHECK_VOID();
  const std::string hmi_level =
  MessageHelper::StringifiedHMILevel(app->hmi_level());
  + if (hmi_level.empty()) {
  + LOG4CXX_WARN(logger_,
  + "HMI level for " << app->policy_app_id() << " is invalid, rpc "
  + << rpc << " is not allowed.");
  + result.hmi_level_permitted = policy::kRpcDisallowed;
  + return;
  + }
  const std::string device_id = MessageHelper::GetDeviceMacAddressForHandle(
  app->device(), application_manager_);
  LOG4CXX_INFO(logger_,
  