Empty types should not be generated in type generation

[maqiuyujoyce]

Checklist

• I did not find a related open enhancement request.
• I understand that enhancement requests filed in the GitHub repository are by default low priority.
• If this request is time-sensitive, I have submitted a corresponding issue with GCP support.

Describe the feature or resource

When I tried to generate the types for AlloyDBCluster using the following command:

go run main.go generate-types \
     --service google.cloud.alloydb.v1beta \
     --api-version "alloydb.cnrm.cloud.google.com/v1beta1" \
     --resource AlloyDBCluster:Cluster \
     --resource AlloyDBInstance:Instance

I found that some of the generated types are actually empty, e.g. EncryptionInfo.

It might be better for us not to write empty types in the generated files.

Additional information

No response

Importance

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