Just use it as any other image and once it finished use the transparency to animate it from 100 to 0. Then use another image at the exact same spot which contains the last image of the animation and change its transparency from 0 to 100. It will look like it runs once and stays at the last frame. Of course you can't loop the menu or if you do, use this trick in the open animation of the UI. It would be nice to have the feature already build in but this is how you can resolve it for now.