Longhorn: Upgrade from 1.6.4. to 1.7.3

Change-Id: I4e713a453a6b9e983685e2db550066fd2694609f
diff --git a/charts/longhorn/templates/preupgrade-job.yaml b/charts/longhorn/templates/preupgrade-job.yaml
index 2b8333d..9f7a8a6 100644
--- a/charts/longhorn/templates/preupgrade-job.yaml
+++ b/charts/longhorn/templates/preupgrade-job.yaml
@@ -20,14 +20,23 @@
       - name: longhorn-pre-upgrade
         image: {{ template "registry_url" . }}{{ .Values.image.longhorn.manager.repository }}:{{ .Values.image.longhorn.manager.tag }}
         imagePullPolicy: {{ .Values.image.pullPolicy }}
+        securityContext:
+          privileged: true
         command:
         - longhorn-manager
         - pre-upgrade
+        volumeMounts:
+        - name: proc
+          mountPath: /host/proc/
         env:
         - name: POD_NAMESPACE
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+      volumes:
+      - name: proc
+        hostPath:
+          path: /proc/
       restartPolicy: OnFailure
       {{- if .Values.privateRegistry.registrySecret }}
       imagePullSecrets: