Fixes #3941. v2win/v2net: UICatalog full benchmark suite crashes in Dialogs scenario (#3963)

Co-authored-by: Tig <[email protected]>

UICatalog/Scenario.cs

@@ -180,7 +180,7 @@ public class Scenario : IDisposable
     }
 
     private List<Key>? _demoKeys;
-    private int _currentDemoKey = 0;
+    private int _currentDemoKey;
 
     private void OnApplicationOnInitializedChanged (object? s, EventArgs<bool> a)
     {
@@ -233,7 +233,6 @@ public class Scenario : IDisposable
     {
         SubscribeAllSubViews (Application.Top!);
 
-        _currentDemoKey = 0;
         _demoKeys = GetDemoKeyStrokes ();
 
         Application.AddTimeout (