In KafkaAgentClient use generic keystore password instead of p12 password

[katheris]

Type of change

Select the type of your PR

• Refactoring

Description

As part of issue 8721 the KafkaAgentClient was swapped to using the PEM certificate rather than the PKCS12 one. However when creating the JKS keystore for the client we still use the PKCS12 password. Since the keystore is never written to disk, the password is never used to verify the keystore, so it shouldn't matter what the password is. This change uses a generic password of "changeit" to remove dependence on the cluster-operator.password value in the Kubernetes secret.

Checklist

Please go through this checklist and make sure all applicable tasks have been done

• Write tests
• Make sure all tests pass
• Update documentation
• Check RBAC rights for Kubernetes / OpenShift roles
• Try your changes from Pod inside your Kubernetes and OpenShift cluster, not just locally
• Reference relevant issue(s) and close them after merging
• Update CHANGELOG.md
• Supply screenshots for visual changes, such as Grafana dashboards

[scholzj]

/azp run regression

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[scholzj]

/azp run kraft-regression

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).