fix wrong ConfigMap for longhorn-storageclass after upgrading

The longhorn-storageclass-override.yaml will be overridden by charts/longhorn after upgrading.
Because longhorn-storageclass-override.yaml only has "post-install" hook, after upgrading, this Configmap will use template of charts/longhorn.

deploy/charts/harvester/templates/longhorn-storageclass-override.yaml

@@ -6,7 +6,7 @@ metadata:
   name: longhorn-storageclass
   namespace: {{ .Values.longhorn.namespaceOverride }}
   annotations:
-    "helm.sh/hook": post-install
+    "helm.sh/hook": post-install,post-upgrade
   labels: {{- include "longhorn.labels" . | nindent 4 }}
 data:
   storageclass.yaml: |
@@ -29,4 +29,4 @@ data:
       {{- if .Values.longhorn.persistence.recurringJobs.enable }}
       recurringJobs: '{{ .Values.longhorn.persistence.recurringJobs.jobList }}'
       {{- end }}
-{{- end -}}
+{{- end -}}