Add support for alternate Model 3 camera file name

[JhottMaster]

This is a really cool app- but when I first tried using it, it would just freeze and not do anything. Looking at the source code I realized it was failing to parse files with a seconds portion of the timestamp in the file name. Not sure if this is a new development in how the files are named or specific to the Model 3, but all my camera file names contained the seconds portion in the file name (e.g. 2019-07-22_17-12-36-front.mp4 instead of 2019-07-22_17-12-front.mp4) so I couldn't view any of the camera files with the app.

This PR provides support for this "new" file name convention as well as the original convention.

[SmartCarrion]

Please merge and build owners!

[JhottMaster]

@SmartCarrion FWIW, I do have a forked repo with the fix. Seems like this project hasn't been active for a while