Fix XamlApp to use CreateWindow for now

Author: PureWeen

src/Controls/samples/Controls.Sample/XamlApp.xaml.cs

@@ -17,8 +17,11 @@ public XamlApp(IServiceProvider services, ITextService textService)
 
 			Debug.WriteLine($"The .NET Purple color is {Resources["DotNetPurple"]}");
 			Debug.WriteLine($"The injected text service had a message: '{textService.GetText()}'");
+		}
 
-			MainPage = Services.GetRequiredService<Page>();
+		protected override Window CreateWindow(IActivationState activationState)
+		{
+			return new Window(Services.GetRequiredService<Page>());
 		}
 
 		public IServiceProvider Services { get; }