fix(StructuredList): fix feature-flag function usage

[tw15egan]

Refs #8931

After working on #9004 with @andreancardona , we realized that the feature-flag function will fail silently if not imported, resulting in weird styling issues like below

Changelog

Changed

• feature-flag-enabled renamed to enabled
• Fixed a spelling error, and updated the feature flag name to the correct one (code)

Testing / Reviewing

StructuredList with Selection should no longer have visible Radio Buttons

cc @sstrubberg

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[kodiakhq]

This PR currently has a merge conflict. Please resolve this and then re-add the status: ready to merge 🎉 label.