Unable to expand Persistence volume, and unable to change the storageClass for zookeeper cluster

[hoyhbx]

Description

(Describe the feature, bug, question, proposal that you are requesting)
We have a zookeeper cluster running, deployed with the operator.
Later we found that the storage is not enough and wish to expand the size of the storage.
So we changed the size of the Persistence volume claim, but the size is not updated.
We later also found that the storageClass cannot be updated neither.

Importance

(Indicate the importance of this issue to you (blocker, must-have, should-have, nice-to-have))
Importance: should-have

Location

(Where is the piece of code, package, or document affected by this issue?)
The field in CRD is spec.persistence.spec.resources.requests.storage.
We found that the statefulSet never updates the PVC.

Suggestions for an improvement

Storage expansion and storageClass change should be supported.
Before they are implemented, any modification to the Persistence field in CR should be rejected.
We recommend to use the CEL feature of Kubernetes to encode the immunity of the field in the CRD

(How do you suggest to fix or proceed with this issue?)