Refactor constructor syntax for Gateway functions to use initializer list

lib/pages/routines/widgets/routine_dialogs/gateway/gateway_dialog.dart

@@ -81,11 +81,8 @@ class _GatewayDialogState extends State<GatewayDialog> {
     final selectedGatewayFunctions = _gatewayFunctions.firstWhere(
       (f) => f.code == selectedFunction,
       orElse: () => GatewaySwitchAlarmSound(
-        code: selectedFunction ?? '',
         deviceId: '',
         deviceName: '',
-        operationName: '',
-        icon: '',
         type: '',
       ),
     );