Bypass the remap CRD version plugin when v1beta1 CRD is not supported (#4706)

When velero is running on clusters that don't support v1beta1 CRD, the
plugin will not try to backup v1beta1 CRD.
The plugin should be kept for backward compatibility.  It will be
removed when velero drop the support for k8s v1.21

Signed-off-by: Daniel Jiang <jiangd@vmware.com>

pkg/cmd/server/plugin/plugin.go

@@ -110,7 +110,16 @@ func newRemapCRDVersionAction(f client.Factory) veleroplugin.HandlerInitializer
 			return nil, err
 		}
 
-		return backup.NewRemapCRDVersionAction(logger, client.ApiextensionsV1beta1().CustomResourceDefinitions()), nil
+		clientset, err := f.KubeClient()
+		if err != nil {
+			return nil, err
+		}
+		discoveryHelper, err := velerodiscovery.NewHelper(clientset.Discovery(), logger)
+		if err != nil {
+			return nil, err
+		}
+
+		return backup.NewRemapCRDVersionAction(logger, client.ApiextensionsV1beta1().CustomResourceDefinitions(), discoveryHelper), nil
 	}
 }