NO-ISSUE: Assign default storage classes on SNO (openshift#4369)

Operations require a default storage class to function properly,
since we are installing those, we can also mark them default:
- Set HPP storage class as default
- LVM Operator takes care of creating and setting its storage class to default:
openshift/lvm-operator#210
So no action required.

Signed-off-by: Alex Kalenyuk <akalenyu@redhat.com>

Signed-off-by: Alex Kalenyuk <akalenyu@redhat.com>

internal/operators/cnv/manifest.go

@@ -211,6 +211,8 @@ spec:
 const cnvHPPStorageClass = `apiVersion: storage.k8s.io/v1
 kind: StorageClass
 metadata:
+  annotations:
+    storageclass.kubernetes.io/is-default-class: "true"
   name: sno-storage
 provisioner: kubevirt.io.hostpath-provisioner
 reclaimPolicy: Delete