All the images follow the same naming schema where the container
name is part of the ansible variable name.  Currently, the
kolla_toolbox container is named ansible_image_full.  Change
this to match what the container name is.

Could impact operators who are specifying ansible_image_full
in globals.yml.

TrivialFix

Change-Id: I9f0cbe4bd69ce17489310a1f5734a254e6ebe27b