Update to #ScreenRec

Just had some time to make some improvements to ScreenRec.

These are the progress I've had. 

1. Stop recording on demand
2. Select a duration from a predefined list (You can still stop the recording anytime)
3. Improved keyboard support
4. Keyboard doesn't randomly appear upon resume and startup

[AlertDialog] List of duration for selection

I'm still working on a lot of things. Like file name generation, and the creation of a modified screenrecord module to make sure that my application can be used to record up to 10 hours (up from the usual 3 minutes). There are just much much more to do. I'll update here accordingly

As always, take care and I'll see you soon :)