Alert user with toast message when reaching video record limit and close file correctly.

[vrzano]

I got the elite battery strap with battery and I was doing a long playtest to test how the charging works while gaming and also I was recording a video for my channel. I played for about 2.5 hours to only find out that the video file capped at 4GB and of course the file wasent closed properly and I lost all my footage.

This seems like an oversight specially since they do sell a "battery extender", and it should be pretty straightforward to implement a warning via toast message that lets the user know the recording will or should stop to prevent corruption. 

@ashley3 has had the same problem, I am just reiterating the idea.