Add yaml vars to focal-ussuri bundle

This brings it into line with the other charms that are part of the the
enable-focal topic.  This makes it easier to add a new bundle just by
changing a couple of variables.

Change-Id: Ib8ad43ce29c1b8048eb095b137265fb5df7e24c0

src/tests/bundles/focal.yaml

@@ -1,21 +1,59 @@
+variables:
+  openstack-origin: &openstack-origin distro
+
 series: focal
-relations:
-- - vault-mysql-router:db-router
-  - mysql-innodb-cluster:db-router
-- - vault:shared-db
-  - vault-mysql-router:shared-db
-- - ovn-central:certificates
-  - vault:certificates
+
+comment:
+- 'machines section to decide order of deployment. database sooner = faster'
+machines:
+  '0':
+    constraints: mem=3072M
+  '1':
+    constraints: mem=3072M
+  '2':
+    constraints: mem=3072M
+  '3':
+  '4':
+  '5':
+  '6':
+
 applications:
+
   mysql-innodb-cluster:
     charm: cs:~openstack-charmers-next/mysql-innodb-cluster
     num_units: 3
+    options:
+      source: *openstack-origin
+    to:
+      - '0'
+      - '1'
+      - '2'
+
   vault-mysql-router:
     charm: cs:~openstack-charmers-next/mysql-router
+
   vault:
     charm: cs:~openstack-charmers-next/vault
     num_units: 1
+    to:
+      - '3'
+
   ovn-central:
-    series: focal
     charm: cs:~openstack-charmers-next/ovn-central
     num_units: 3
+    options:
+      source: *openstack-origin
+    to:
+      - '4'
+      - '5'
+      - '6'
+
+relations:
+
+  - - 'vault:shared-db'
+    - 'vault-mysql-router:shared-db'
+  - - 'vault-mysql-router:db-router'
+    - 'mysql-innodb-cluster:db-router'
+
+  - - 'ovn-central:certificates'
+    - 'vault:certificates'