Video Texture thumbnail does not update after you change its output track

When updating a video texture's output track, the player preview and world will update immediately, however the texture's thumbnail will revert to default color: Black.
When moused over, the thumbnail will update to the current output track.

Worked in: 4.15.1 - 3328138

1. Create a Media Player
   • Leave Audio and Video Output checkboxes blank
2. Create a Media Texture
3. Open the Media Player
   1. Drag the Media Texture from the Content Browser into the Output>Video Texture section
4. Open the Media Texture
   1. Change the Clear Color to any color other than default
5. Go back to the Media Player Window

Result: Preview is updated, Video Texture Thumbnail is Black
Expected Result: Preview and Video Texture Thumbnail are updated