convert response headers after setting content

Otherwise, we end up overwriting `response.Content.Headers`.

Signed-off-by: Joel Dice <[email protected]>

Author: dicej

src/libraries/System.Net.Http/src/System/Net/Http/WasiHttpHandler/WasiHttpHandler.cs

@@ -57,15 +57,14 @@ public async Task<HttpResponseMessage> SendRequestAsync(HttpRequestMessage reque
                 cancellationToken.ThrowIfCancellationRequested();
 
                 var response = new HttpResponseMessage((HttpStatusCode)incomingResponse.Status());
-                WasiHttpInterop.ConvertResponseHeaders(incomingResponse, response);
-
 
                 // request body could be still streaming after response headers are received and started streaming response
                 // we will leave scope of this method
                 // we need to pass the ownership of the request and this wrapper to the response (via response content stream)
                 // unless we know that we are not streaming anymore
                 incomingStream = new WasiInputStream(this, incomingResponse.Consume());// passing self ownership, passing body ownership
                 response.Content = new StreamContent(incomingStream); // passing incomingStream ownership to SendAsync() caller
+                WasiHttpInterop.ConvertResponseHeaders(incomingResponse, response);
 
                 return response;
             }