Longhorn: Upgrade from 1.7.3 to 1.8.1

Change-Id: Ie2076df97ee3d00cbced65ad52888d3b467725d4
diff --git a/charts/longhorn-1.7.3/templates/network-policies/recovery-backend-network-policy.yaml b/charts/longhorn-1.7.3/templates/network-policies/recovery-backend-network-policy.yaml
new file mode 100644
index 0000000..37bf5f9
--- /dev/null
+++ b/charts/longhorn-1.7.3/templates/network-policies/recovery-backend-network-policy.yaml
@@ -0,0 +1,17 @@
+{{- if .Values.networkPolicies.enabled }}
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: longhorn-recovery-backend
+  namespace: {{ include "release_namespace" . }}
+spec:
+  podSelector:
+    matchLabels:
+      longhorn.io/recovery-backend: longhorn-recovery-backend
+  policyTypes:
+  - Ingress
+  ingress:
+  - ports:
+    - protocol: TCP
+      port: 9503
+{{- end }}