re-visit the need to restart the schema registry service after performing updates

[chrisseto]

The helm chart's post upgrade hook performs a restart of the schema registry service utilizing the admin api's debug endpoints. It's suspected that this is being performed to handle transitions to and from SASL being enabled on the cluster but we're not 100% certain about this.

We need to add some tests that enable and then disable SASL so we can assert whether or not such a hook is required for stable operations.

See Also:

• add sync-cluster-config command #231
• chore: restart schema registry on upgrade helm-charts#846

JIRA Link: K8S-361