Update configuration in cert-manager example

This provides more valid domain name that can be used in the
example.

Author: Jonathan S. Katz

kustomize/certmanager/postgres/cert.yaml

@@ -12,7 +12,7 @@ spec:
     - hippo-org
   # The use of the common name field has been deprecated since 2000 and is
   # discouraged from being used.
-  commonName: postgres-operator
+  commonName: hippo-primary
   isCA: false
   privateKey:
     algorithm: ECDSA
@@ -23,6 +23,9 @@ spec:
   # At least one of a DNS Name, URI, or IP address is required.
   dnsNames:
   - hippo-primary
+  - hippo-primary.postgres-operator
+  - hippo-primary.postgres-operator.svc
+  - hippo-primary.postgres-operator.svc.cluster.local
   issuerRef:
     name: ca-issuer
     # We can reference ClusterIssuers by changing the kind here.