democratic-csi: Enable volume snapshot support

The _democratic-csi_ controller can create Synology LUN snapshots based
on VolumeSnapshot resources.  This feature can be used to e.g. create
data snapshots before upgrades, etc.

democratic-csi/secrets.yaml

@@ -37,6 +37,10 @@ spec:
             max_sessions: 0  # 0: Unlimited
             chap: true
             mutual_chap: true
+          lunSnapshotTemplate:
+            is_app_consistent: true
+            is_locked: true
+
 ---
 apiVersion: bitnami.com/v1alpha1
 kind: SealedSecret