Update k8s validate clusters testdata when grouping is supported in drenv

[parikshithb]

The k8s testdata in testdata/clusters/k8s/validate-clusters.data/hub/cluster/ramendr.openshift.io/drpolicies/* needs to be updated to include the grouping once consistency group support is available in drenv and also update TestValidateClustersK8s test expectation to include Grouping field in PeerClassesSummary.

Value: []report.PeerClassesSummary{
    {
        StorageClassName: "rook-ceph-block",
        ReplicationID:    "rook-ceph-replication-1",
        // Grouping field missing
    },
    // ...
},