Add collection of app usage (like Digital Wellbeing dashboard)

[barbeau]

Is your feature request related to a problem? Please describe.
Android has Digital Wellbeing info now that includes app usage info:
https://wellbeing.google/tools/

Describe the solution you'd like
It would be nice to collect this information to we have a baseline of how much time the user has spent using MUSER.

We need to consider the potential impacts of asking for additional permissions for this. It's likely fine for enrolled users in research studies but could drive away casual users. But given that our entire audience is users in research projects now, it should be fine.