Does OSB always add "charset" parameter to Content-Type header?

Hi there!

Running Weblogic and OSB 12.2.1.3 with Java 8

We have a header (in tran:headers) defined in the pipeline as

<http:Content-Type>application/json</http:Content-Type>

but something -before reaching the BS- sets it to

<http:Content-Type>application/json; charset=utf-8</http:Content-Type>

and that means getting an error from an external provider, since they expect a "clean" Content-Type, with no parameters.

We're trying to understand if this behavior is indeed happening at the OSB layer/level. And if there's a setting/way/workaround to avoid it on a global or -preferably- service level, since it doesn't honor our pipeline and it doesn't seem to be compliant with