private boolean usesAwsProtocol(ServiceShape service, ServiceIndex index) {
        for (Trait protocol : index.getProtocols(service).values()) {
            if (protocol instanceof AwsProtocolTrait) {
                return true;
            }
        }
        return false;
    }
Ensures that the http payload trait is only bound to structures, unions,
documents, blobs, or strings for AWS protocols.
smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/protocols/ProtocolHttpPayloadValidator.java