Change image names to match what the rest of the system expects

The image names in other parts of the TripleO ecosystem are
overcloud-full and ironic-python-agent. Other parts are expecting
these names. This changes the default yaml to match.

Change-Id: Ia1a3fa071c07d8a60c69f32375ac6b0aa92cff7b

image-yaml/overcloud-images-centos7.yaml

@@ -1,13 +1,13 @@
 disk_images:
   -
-    imagename: overcloud
+    imagename: overcloud-full
     arch: amd64
     type: qcow2
     distro: centos7
     elements:
       - selinux-permissive epel
   -
-    imagename: ramdisk_agent
+    imagename: ironic-python-agent
     arch: amd64
     type: qcow2
     distro: centos7

image-yaml/overcloud-images-rhel7.yaml

@@ -1,11 +1,11 @@
 disk_images:
   -
-    imagename: overcloud
+    imagename: overcloud-full
     arch: amd64
     type: qcow2
     distro: rhel7
   -
-    imagename: ramdisk_agent
+    imagename: ironic-python-agent
     arch: amd64
     type: qcow2
     distro: rhel7

image-yaml/overcloud-images.yaml

@@ -1,6 +1,6 @@
 disk_images:
   -
-    imagename: overcloud
+    imagename: overcloud-full
     arch: amd64
     type: qcow2
     elements:
@@ -19,7 +19,7 @@ disk_images:
     options:
       - "--min-tmpfs 5"
   -
-    imagename: ramdisk_agent
+    imagename: ironic-python-agent
     arch: amd64
     type: qcow2
     elements: