[EKS] [request]: Support podIdentityAssociations in EKS Community Add-ons "cert-manager"

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**Tell us about your request**
Please support podIdentityAssociations in the EKS Community Add-ons "cert-manager".

**Which service(s) is this request for?**
EKS Add-ons

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
Currently, specifying the podIdentityAssociations parameter when creating EKS Community Add-ons "cert-manager" fails.

```
❯ aws eks create-addon \
--cluster-name CLUSTER_NAME \
--addon-name cert-manager \
--addon-version v1.19.1-eksbuild.1 \
--pod-identity-associations serviceAccount=cert-manager,roleArn=ROLE_ARN

An error occurred (InvalidParameterException) when calling the CreateAddon operation: Pod Identity feature is not supported for addon version: v1.19.1-eksbuild.1
```

Executing the following separately increases management costs:
- Creating EKS Community Add-ons "cert-manager"
- Configuring Pod Identity

**Are you currently working around this issue?**
After creating EKS Community Add-ons "cert-manager", we need to configure Pod Identity separately.

Start with the aws eks create-addon example and the cert-manager add-on version named in the issue. Investigate how podIdentityAssociations are handled for this add-on; done means creating the add-on with that parameter succeeds without the reported unsupported-feature error.

Written by the indexing model from the issue text.