Fix validation of key_path block.

[christinaholtNOAA]

Synopsis

Follow up to previous change to naming conventions of the Driver config attributes. When a key_path is provided, use the block within the key_path to validate the platform section as well.

Type

• Bug fix (corrects a known issue)
• Code maintenance (refactoring, etc. without behavior change)
• Documentation
• Enhancement (adds new functionality)
• Tooling (CI, code-quality, packaging, revision-control, etc.)

Impact

• This is a breaking change (changes existing functionality)
• This is a non-breaking change (existing functionality continues to work as expected)

Checklist

• I have added myself and any co-authors to the PR's Assignees list.
• I have reviewed the documentation and have made any updates necessitated by this change.

[maddenp-noaa]

This looked so familiar until I realize that I made this fix -- but only on the Assets class, not on Driver. Sorry about that.