[BUG] Cluster volumeClaimTemplates does not take effect

[yimeisun]

Describe the bug
User creates cluster without volumeClaimTemplates first, and update cluster with volumeClaimTemplates, but the volume does not take effect.

To Reproduce

1. cd kubeblocks
2. make manifests && make generate && make install
3. start kubeblocks with IDE
4. cd deploy/prometheus-cluster && helm dependency build
5. helm upgrade --install kb-addon-prometheus . --set="nameOverride=playground,server.persistence.enable=false"
6. helm upgrade --install kb-addon-prometheus . --set="nameOverride=playground,server.persistence.enabled=true"

Expected behavior
After step 5), the data volume in created cluster prometheus is EmptyDir,
After step 6), the data volume in created cluster prometheus is PersistentVolumeClaim.