bug fixes (material 5)

com.unity.uiwidgets/Runtime/animation/animation_controller.cs

 
                 return true;
             });
+            _ticker.Dispose();
             _ticker = null;
             base.dispose();
         }

com.unity.uiwidgets/Runtime/material/material_button.cs

 
             return new RawMaterialButton(
                 onPressed: onPressed,
-                onLongPress:() => onLongPress(),
+                onLongPress:() => onLongPress?.Invoke(),
                 enableFeedback: enableFeedback?? true,
                 onHighlightChanged: onHighlightChanged,
                 fillColor: buttonTheme.getFillColor(this),