Handle header_params same as upstream (#410)

Co-authored-by: Fabian von Feilitzsch <[email protected]>

Author: openshift-cherrypick-robot

openshift/dynamic/client.py

@@ -186,7 +186,7 @@ def watch(self, resource, namespace=None, name=None, label_selector=None, field_
             yield event
 
     @meta_request
-    def request(self, method, path, body=None, accept_header=None, **params):
+    def request(self, method, path, body=None, **params):
         if not path.startswith('/'):
             path = '/' + path
 
@@ -216,12 +216,14 @@ def request(self, method, path, body=None, accept_header=None, **params):
         header_params = params.get('header_params', {})
         form_params = []
         local_var_files = {}
-        # HTTP header `Accept`
-        header_params['Accept'] = accept_header or self.client.select_header_accept([
-            'application/json',
-            'application/yaml',
-            'application/vnd.kubernetes.protobuf'
-        ])
+
+        # Checking Accept header.
+        new_header_params = dict((key.lower(), value) for key, value in header_params.items())
+        if not 'accept' in new_header_params:
+            header_params['Accept'] = self.client.select_header_accept([
+                'application/json',
+                'application/yaml',
+            ])
 
         # HTTP header `Content-Type`
         if params.get('content_type'):