Avatar Chooser

A dialog that allows the user to set a profile picture.

Participants

Allow selecting the a picture for a user account:
- Profile pictures from online accounts
- Take a picture using the camera
- Pick from a set of nice stock images (primarily of use when there aren't online accounts and/or there's no camera)
Potential uses - user settings, initial setup, Contacts
Ensure that users don't end up with a generic default profile picture - generate a unique image for each user and use that as a fallback