Support taking or choosing a photo in avatar picker.

This adds options to take a photo or to choose a photo to
the new avatar picker.

The functionality to support both of these operations, plus
cropping, is largely the same as before but has been moved
from EditUserPhotoController to a new AvatarPhotoController.

The code from EditUserPhotoController has been moved without
changes where possible. Future CLs may introduce improvements
such as replacing AsyncTask.

The 'choose photo' has been changed from the previous behaviour,
however - it now shows the new photo picker.

Bug: 215134398
Test: manual, check new UI from settings and sysui and confirm working
Change-Id: I5d98902f3e8c186ad30d288b8eed544977ba0e48