Update ApiClient.mustache

Author: arcueid-dev

modules/openapi-generator/src/main/resources/csharp/libraries/unityWebRequest/ApiClient.mustache

@@ -274,6 +274,16 @@ namespace {{packageName}}.Client
                 request = UnityWebRequest.Post(uri, form);
                 request.method = method;
             }
+            else if (options.Data is Stream stream)
+            {
+                using (var binaryReader = new BinaryReader(stream))
+                {
+                    var bytes = binaryReader.ReadBytes((int)stream.Length);
+                    request = UnityWebRequest.Put(uri, bytes);
+                    request.method = method;
+                    request.SetRequestHeader("Content-Type", "application/octet-stream");
+                }
+            }
             else if (options.Data != null)
             {
                 var serializer = new CustomJsonCodec(SerializerSettings, configuration);