Change template context generation in TemplateHTMLRenderer (#4236)

- Change the name of ``resolve_context()`` to ``get_template_context()``.
- Pass the renderer context to this method, to give subclasses more flexibility
  when overriding.

rest_framework/renderers.py

@@ -166,13 +166,14 @@ class TemplateHTMLRenderer(BaseRenderer):
             template_names = self.get_template_names(response, view)
             template = self.resolve_template(template_names)
 
-        context = self.resolve_context(data, request, response)
+        context = self.get_template_context(data, renderer_context)
         return template_render(template, context, request=request)
 
     def resolve_template(self, template_names):
         return loader.select_template(template_names)
 
-    def resolve_context(self, data, request, response):
+    def get_template_context(self, data, renderer_context):
+        response = renderer_context['response']
         if response.exception:
             data['status_code'] = response.status_code
         return data