The drop root change for Glance highlighted the fact that we were
binding volumes from glance_data into the wrong container - it was
glance_registry whereas it should be glance_api. This would result in
all images being lost if the glance_api container happens to restart.
Also, we need a sudoers file to chown the file backend dir to the glance
user.
Change-Id: If04337045bb94b3126e48d1f5bf0ea29e20373ae
Closes-Bug: #1516729