Adjust the statefulset naming convention shorter to accommodate longer registry name

[krimeshshah]

How to categorize this issue?

/kind bug

We were investigating on using the gardener registry cache extension following this document https://github.com/gardener/gardener-extension-registry-cache/blob/v0.3.0/docs/usage/configuration.md. After adding the list of registry in the extension , reconciliation of the cluster fails due to some of registry FQDN has a longername and in addition, creation of pod and stateful set adds "registry" word as a prefix which makes the name more longer and causes the failure in the creation of pod and statefulset.

Error :
create Pod registry-deploy-releases-common-repositories-cloud-sap-0 in StatefulSet registry-deploy-releases-common-repositories-cloud-sap failed error: Pod "registry-deploy-releases-common-repositories-cloud-sap-0" is invalid: metadata.labels: Invalid value: "registry-deploy-releases-common-repositories-cloud-sap-f988b5f85": must be no more than 63 characters**: 

Why is this needed:

[gardener-prow]

@krimeshshah: The label(s) area/todo cannot be applied, because the repository doesn't have them.

In response to this:

How to categorize this issue?

/area TODO
/kind enhancement

What would you like to be added We were investigating on using the gardener registry cache extension following this document https://github.com/gardener/gardener-extension-registry-cache/blob/v0.3.0/docs/usage/configuration.md. After adding the list of registry in the extension , reconciliation of the cluster fails due to some of registry FQDN has a longername and in addition, creation of pod and stateful set adds "registry" word as a prefix which makes the name more longer and causes the failure in the creation of pod and statefulset.
Error :
create Pod registry-deploy-releases-common-repositories-cloud-sap-0 in StatefulSet registry-deploy-releases-common-repositories-cloud-sap failed error: Pod "registry-deploy-releases-common-repositories-cloud-sap-0" is invalid: metadata.labels: Invalid value: "registry-deploy-releases-common-repositories-cloud-sap-f988b5f85": must be no more than 63 characters:

Why is this needed:

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.