Better import experience when Google's apps not installed

[patcon]

This is only a concern for those who are not syncing contacts/calendars via Google on their device.

Contact import doesn't necessarily need to happen via a custom wizard, but it might make sense to recommend some tools for import. I'll be testing these, and will report back:

• https://f-droid.org/repository/browse/?fdfilter=import&fdid=am.ed.importcontacts
• https://f-droid.org/repository/browse/?fdfilter=import&fdid=org.dgtale.icsimport
• https://f-droid.org/repository/browse/?fdfilter=import&fdid=de.k3b.android.calendar.ics.adapter