Helidon connector should honor Content-Length header

[spericas]

Problem Description

When using the Helidon connector, it appears that Content-Length is not honored, resulting in the use of transfer encoding instead. This could be due a bug in the connector or some logic in WebClient.

Steps to reproduce

From the user's channel:

ClientConfig clientConfig = new ClientConfig();
clientConfig.connectorProvider(new HelidonConnectorProvider());
//..timeout settings

ClientBuilder clientBuilder = ClientBuilder.newBuilder().withConfig(clientConfig);

Client client = clientBuilder.build();
Builder requestBuilder = client.target(url).request();

// request preparation
requestBuilder = requestBuilder.headers(headers);
Entity<?> payload = Entity.entity(payload, mediaType);//json media type and string payload
Response response = requestBuilder.post(payload);

In the headers we are adding HttpHeaders.CONTENT_LENGTH as well with value - payload.getBytes(StandardCharsets.UTF_8).length