[global_unity_controller] Fix dispose not called#769

Ortes wants to merge 1 commit intojuicycleff:feat/global_unity_controllerjuicycleff/flutter-unity-view-widget:feat/global_unity_controllerfrom

Ortes:fix/global_unity_controller/disposeOrtes/flutter-unity-view-widget:fix/global_unity_controller/disposeCopy head branch name to clipboard