Increase default http.max_header_size to 16kb

Signed-off-by: 10000-ki <[email protected]>

Author: 10000-ki

server/src/main/java/org/opensearch/http/HttpTransportSettings.java

@@ -151,7 +151,7 @@ public final class HttpTransportSettings {
     );
     public static final Setting<ByteSizeValue> SETTING_HTTP_MAX_HEADER_SIZE = Setting.byteSizeSetting(
         "http.max_header_size",
-        new ByteSizeValue(8, ByteSizeUnit.KB),
+        new ByteSizeValue(16, ByteSizeUnit.KB),
         Property.NodeScope
     );
     public static final Setting<Integer> SETTING_HTTP_MAX_WARNING_HEADER_COUNT = intSetting(