Fixes SkiaRenderer not propagating the right transformation during …

…its Notify calls (came up in #673)

VL.Stride.Runtime/src/SkiaRenderer.InputHandling.cs

@@ -23,7 +23,7 @@ IDisposable SubscribeToInputSource(IInputSource inputSource, RenderDrawContext c
             return inputManager.GetNotifications(inputSource, sender: this)
                 .Subscribe(n =>
                 {
-                    Layer?.Notify(n, callerInfo);
+                    viewportLayer.Notify(n, callerInfo);
                 });
         }
     }