updated key name to available_roof_area_sqft

[rawadelkontar]

Resolves #[issue number here]

Pull Request Description

[description here]

Checklist (Delete lines that don't apply)

• [ ] Unit tests have been added or updated
• [ ] Documentation has been modified appropriately
• [ ] All ci tests pass (green)
• [ ] An issue has been created (which will be used for the changelog)
• [ ] This branch is up-to-date with develop