Update UI chart to create a more supportable approach to overriding images

[mgianatagh]

When the command "ocne cluster start --provider none --kubeconfig $KUBECONFIG --auto-start-ui false" is used to add the UI and once-catalog to an existing cluster, the registry to use for

The registry to pull container images from can be overridden by the "registry" value in ~/.ocne/defaults.yaml. When the command "ocne cluster start --provider none --kubeconfig $KUBECONFIG --auto-start-ui false" is used, the deployments for ocne-catalog and ui need to have helm overrides applied to use the registry value. The implementation of this feature was complicated by needing to override the image: tag in an init-container. The logic needed to reapply the entire init container.

This task is to determine how to simplify the helm chart so the CLI logic can just override the image tag, without knowing the complete definition of the init-container.

Notes:

• This task will require changes to the CLI and catalog.
• The UI helm chart could be changed to have the init-container in the deployment template (instead of a helm value) and the value for the image could be controlled by a single value in the values.yaml. The CLI logic could then be simplified to just override the image value.
• The change needs to be compatible with the existing CLI. It is possible for a user environment to have a CLI that expects to override the complete init-container definition, and have an app-catalog that has an updated helm chart for the UI that does not require the init container override.