message: only set language in rai response if it is valid
diff: @@ -557,7 +557,10 @@ RegisterAppInterfaceRequest::GetLockScreenIconUrlNotification(
  void FillVRRelatedFields(smart_objects::SmartObject& response_params,
  const HMICapabilities& hmi_capabilities) {
  - response_params[strings::language] = hmi_capabilities.active_vr_language();
  + auto active_vr_lang = hmi_capabilities.active_vr_language();
  + if (hmi_apis::Common_Language::INVALID_ENUM != active_vr_lang) {
  + response_params[strings::language] = active_vr_lang;
  + }
  auto vr_capabilities = hmi_capabilities.vr_capabilities();
  if (vr_capabilities) {
  response_params[strings::vr_capabilities] = *vr_capabilities;
  @@ -574,7 +577,10 @@ void FillVIRelatedFields(smart_objects::SmartObject& response_params,
  void FillTTSRelatedFields(smart_objects::SmartObject& response_params,
  const HMICapabilities& hmi_capabilities) {
  - response_params[strings::language] = hmi_capabilities.active_tts_language();
  + auto active_tts_lang = hmi_capabilities.active_tts_language();
  + if (hmi_apis::Common_Language::INVALID_ENUM != active_tts_lang) {
  + response_params[strings::language] = active_tts_lang;
  + }
  auto speech_capabilities = hmi_capabilities.speech_capabilities();
  if (speech_capabilities) {
  response_params[strings::speech_capabilities] = *speech_capabilities;
  @@ -587,8 +593,10 @@ void FillTTSRelatedFields(smart_objects::SmartObject& response_params,
  void FillUIRelatedFields(smart_objects::SmartObject& response_params,
  const HMICapabilities& hmi_capabilities) {
  - response_params[strings::hmi_display_language] =
  - hmi_capabilities.active_ui_language();
  + auto active_ui_lang = hmi_capabilities.active_ui_language();
  + if (hmi_apis::Common_Language::INVALID_ENUM != active_ui_lang) {
  + response_params[strings::hmi_display_language] = active_ui_lang;
  + }
  auto display_capabilities = hmi_capabilities.display_capabilities();
  if (display_capabilities) {
  