Story

With the addition of the new OSImageStream.spec.defaultStream field we would need to validate that the user inputs are valid.

This change is about adding a small API validation rule that ensures the field is validated based on the status streams. If the status has not been yet reported there's no validation to apply.

Acceptance Criteria

• The field is validated to ensure that, when given, its value points to a stream available in OSImageStream.status.availableStreams.
• If the status has not been set yet no validation should be performed.