Simplify runner enabled config

What does this Merge Request do?

• Simplify runner.enabled boolean logic
• Add additional test

Closes #821 (closed)

Merge Request checklist

• Tests added for new functionality. If not, please raise Issue to follow-up.
• This change is backward compatible. If not, please include steps to communicate to our users.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.