"Invalid Swift Support" Using Native Swift Library in Xamarin.iOS

I just implemented a native library, Charts (original native library), and its working on my phone and simulator. Unfortunately, when I submit it to iTunes connect, it kicks it back after processing and says:

Invalid Swift Support - The SwiftSupport folder is missing. Rebuild your app using the current public (GM) version of Xcode and resubmit it.

I'm using XCode to publish the archive to iTunes connect, but don't know how to do what this StackOverflow solution is saying. Since I don't use XCode to start the build process, I'm using Xamarin Studio 6, not sure how to set that setting.

So ideally, I need to "Set the flag EMBEDDED_CONTENT_CONTAINS_SWIFT to YES in the target settings".

Anybody have any ideas on how to do this? At a roadblock on releasing the beta until I can get this uploaded.

Thanks for your help!