Screen interactive watcher

Thanks for working on ActivityWatch, really an amazing project!

In addition to #35 I'd find it useful and interesting to also have a bucket that tracks the screen going into interactive state. Often enough phones are checked by waking the display but not actually unlocking.

Based on the description I'd assume this should be covered by [SCREEN_INTERACTIVE](https://developer.android.com/reference/android/app/usage/UsageEvents.Event#SCREEN_INTERACTIVE). If this would be considered in general, I'd also be interested in working on it.