added localization for excursion steps

lib/screens/excursion/excursion_main.dart

@@ -250,7 +250,7 @@ class _ExcursionMainState extends State<ExcursionMain> {
         ),
       ),
       Step(
-        title: const Text("step2"),
+        title: Text(AppLocalizations.of(context)!.umstaendeUndAktionen),
         content: Column(
           children: [
             // ---------- Weather
@@ -324,7 +324,7 @@ class _ExcursionMainState extends State<ExcursionMain> {
         ),
       ),
       Step(
-        title: const Text("step3"),
+        title: Text(AppLocalizations.of(context)!.intkomm),
         content: Column(
           children: [
             // ---------- Remarks