policies: fix policybinding API returning wrong policy objects

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/api/templates/api/swagger.html

@@ -15,6 +15,7 @@ authentik API Browser
     spec-url="{{ path }}"
     heading-text="authentik"
     theme="dark"
+    render-style="view"
     primary-color="#fd4b2d"
     allow-spec-url-load="false"
     allow-spec-file-load="false">

authentik/policies/api/bindings.py

@@ -102,8 +102,8 @@ class PolicyBindingViewSet(ModelViewSet):
     """PolicyBinding Viewset"""
 
     queryset = PolicyBinding.objects.all().select_related(
-        "policy", "target", "group", "user"
-    )
+        "target", "group", "user"
+    ).prefetch_related("policy") # prefetching policy so we resolve the subclass
     serializer_class = PolicyBindingSerializer
     filterset_fields = ["policy", "target", "enabled", "order", "timeout"]
     search_fields = ["policy__name"]