Fix issue with iamidentitymapping

[username72764274]

Description

This should fix issues similar to #4329, where an ebs volume could not be created, due to missing aws-cn references.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[cPu1]

Thanks for the PR. Can you add a unit test for this change in pkg/cfn/builder/iam_test.go?

[username72764274]

I could try. However, after a first glance at the tests in pkg/cfn/builder/iam_test.go I think it will take me some time to figure out, how to add a proper unit-test there. So I guess it would make more sense, if someone adds a test who is more familiar with the test setup.

[jonathan-strzalka-saggs]

+1

[Skarlso]

This PR has been fixed by #4547. Thank you for your contribution, sorry, I didn't realise that this was also working on that part.