WmfMedia: Calling the play and pause nodes multiple times cause a media player to stop working

If the player calls the nodes Pause > Play > Pause > Play, the media player will stop working.

1. Open the the Content Examples project
2. Open the Media level
3. Open the level blueprint
4. Create the blueprint in the attached image
5. Play In Stand alone mode
6. Walk up to the Media player widget booth
7. Notice that the media player comes up blank and is unresponsive

Expected: The player should stop, start, stop, start and maintain the ability to be interacted with
Result: The media player no longer functions