once the user opted into recommendations the profile needs to be updated regularly

The current code in recommendations.py indicates that the users recommendations profile is only uploaded
once when the user opts-in:

def _on_opt_in_button_clicked(self, button):
        # we upload the user profile here, and only after this is finished
        # do we fire the request for recommendations and finally display
        # them here -- a spinner is shown for this process (the spec
        # wants a progress bar, but we don't have access to real-time
        # progress info)
        self._upload_user_profile_and_get_recommendations()

This needs to get fixed, ideally we submit the profile on each startup if it changed, to detect changes
we could store a simple hash of the pkgnames in the profile.