CI: Disable disk image build in seed-upgrade jobs

This build takes time and can fail due to lack of disk space. It got
enabled when we changed overcloud_dib_build_host_images to true.

Also fix bifrost overrides which was wrongly applied, we need to use
dib.yml instead of bifrost.yml, like in kayobe-seed-base.

Change-Id: I1edafbb41a26587a5ef794b3b9886fdf189a0a1a

playbooks/kayobe-seed-upgrade-base/overrides.yml.j2

@@ -24,6 +24,10 @@ pip_index_url: "http://{{ zuul_site_mirror_fqdn }}/pypi/simple"
 pip_trusted_hosts:
   - "{{ zuul_site_mirror_fqdn }}"
 
+# Disable overcloud host disk image build. The image build in Bifrost is
+# disabled via bifrost-overrides.yml.j2.
+overcloud_dib_build_host_images: False
+
 # NOTE(mgoddard): CentOS 8 removes interfaces from their bridge during ifdown,
 # and removes the bridge if there are no interfaces left. When Kayobe bounces
 # veth links plugged into the bridge, it causes the bridge which has the IP we

playbooks/kayobe-seed-upgrade-base/pre.yml

@@ -30,7 +30,8 @@
         path: "{{ previous_kayobe_config_src_dir }}/etc/kayobe/kolla/config/bifrost"
         state: "directory"
 
+    # NOTE(mgoddard): Use dib.yml, since it takes precedence over bifrost.yml.
     - name: Ensure bifrost overrides file exists
       template:
         src: bifrost-overrides.yml.j2
-        dest: "{{ previous_kayobe_config_src_dir }}/etc/kayobe/kolla/config/bifrost/bifrost.yml"
+        dest: "{{ previous_kayobe_config_src_dir }}/etc/kayobe/kolla/config/bifrost/dib.yml"

playbooks/kayobe-seed-upgrade-base/run.yml

@@ -36,7 +36,7 @@
         remote_src: true
       with_items:
         - etc/kayobe/kolla/passwords.yml
-        - etc/kayobe/kolla/config/bifrost/bifrost.yml
+        - etc/kayobe/kolla/config/bifrost/dib.yml
 
     # NOTE(mgoddard): Use the name zz-overrides.yml to ensure this takes
     # precedence over the standard config files.