Only uses multipart when dealing with file fields

https://pulp.plan.io/issues/6702
closes #6702

CHANGES/6702.bugfix

@@ -0,0 +1 @@
+Only uses multipart OpenAPI Schema when dealing with `file` fields

pulpcore/app/openapigenerator.py

@@ -320,16 +320,17 @@ def get_operation(self, operation_keys):
         consumes = self.get_consumes()
         produces = self.get_produces()
 
+        body = self.get_request_body_parameters(consumes)
+
         multipart = ["multipart/form-data", "application/x-www-form-urlencoded"]
         if self.method != "GET":
-            request_params = self.get_request_body_parameters(multipart)
-            type_list = [param["type"] for param in request_params if param]
-            if "file" in type_list:
+            type_list = [param["type"] for param in body if param]
+            if "file" in type_list and consumes != multipart:
                 # automatically set the media type to form data if there's a file
                 # needed due to https://github.com/axnsan12/drf-yasg/issues/386
                 consumes = multipart
+                body = self.get_request_body_parameters(consumes)
 
-        body = self.get_request_body_parameters(consumes)
         query = self.get_query_parameters()
         if self.method == "GET":
             fields_paramenter = Parameter(