fix intermittent failures when deploying base glance images

CI testing is experiencing intermittent failures when deploying base glance
images as part of the openstack-image-setup.yml playbook which is kicked of
as part of the openstack-service-setup.yml playbook in openstack-ansible-ops.
Since the deployment of these resources rely on external URI endpoints, this
type of failure is something that can occur during a customer deployment.

Change-Id: Ieea0f11482646ea152920a1ff1009a2b03705f1c

multi-node-aio/playbooks/openstack-image-setup.yml

@@ -7,6 +7,11 @@
     url: "{{ item.url }}"
     dest: "/tmp/os_image_{{ item.name }}"
     timeout: 600   # big files might take a while to download
+  register: download_result
+  until: download_result|succeeded
+  retries: 10
+  delay: 15
+  failed_when: download_result is failure
 
 - name: Install system image
   os_image: