[IMP] endpoint_route_handler: add request_content_type application_js…

…on_utf8

endpoint_route_handler/models/endpoint_route_handler.py

@@ -129,6 +129,7 @@ def _selection_request_content_type(self):
             ("application/json", "JSON"),
             ("application/xml", "XML"),
             ("application/x-www-form-urlencoded", "Form"),
+            ("application/json; charset=utf-8", "JSON_UTF8 (Deprecated)"),
         ]
 
     @api.depends(lambda self: self._routing_impacting_fields())