Add-on update on the fly for custom storage class

Recently we did an update of add-on vpc-block-csi-driver to version 4.2 and we noticed that all default storage classes are now extendable, I mean all have allowVolumeExpansion:true parameter. Some other changes also have been done and all "on the fly".

However the custom storage classes were not updated. The only way to have a consistent environment is to make changes manually, according to the documentation: https://cloud.ibm.com/docs/containers?topic=containers-vpc-block#recreate-sc-42%22
where it is recommended to copy date, edit the custom storage classes to remove/add parameters. To change the parameters in custom storage classes, we must delete and recreate them.

However logically if disable and enable add-on updated default storage classes with add-on 4.2, without coping data and destroying storage classes, this should be also possible for custom storage class.

"The Block Storage for VPC add-on is installed and enabled by default on VPC clusters. Later, you can disable or reenable the add-on by using the addon disable or addon enable command in the CLI. PVC creation and app deployment are not disrupted when the add-on is disabled. Existing volumes and data are not impacted."