Updated AdAssetFeedSpec with new promotional_metadata field ( AdAssetPromotionalMetadata )

[Just1B]

Checklist

• [x] I've read the Contributing Guidelines and the Code of Conduct
• [x] I've completed the Contributor License Agreement

Pull Request Details

Updated AdAssetFeedSpec adobject with new promotional_metadata field based on API responses observation

The Field appear in the documentation but the Adboject Doc is empty

First time seeing this field in my system : 2024-03-26

https://developers.facebook.com/docs/marketing-api/reference/ad-asset-feed-spec/#fields

Api Responses :