[bitnami/postgresql] Add Storage Class Configuration to Templates

[3schwartz]

Description of the change

Add configurations to the template.

Benefits

It is possible to define a storage class.

Applicable issues

Currently not able to define the storage class even though the configuration in the values.yaml file is there.

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

[carrodher]

Thanks for your contribution! Please note to test the Helm charts it is needed to split the changes of each chart into separate PRs

[3schwartz]

Thanks for your contribution! Please note to test the Helm charts it is needed to split the changes of each chart into separate PRs

Made a second PR
#30993

[fmulero]

Thanks a lot @3schwartz for your contribution!

Just a quick suggestion, Could you add this change to read replicas also? the value readReplicas.persistence.storageClass already exists so the change should be the same for the read replicas statefulset

[3schwartz]

readReplicas.persistence

✅

[fmulero]

Great!!. Thanks @3schwartz LGTM