properly sanitize encrypted default passwords in JT.survey_spec

see: https://github.com/ansible/ansible-tower/issues/7259

awx/api/views.py

@@ -2851,13 +2851,8 @@ class JobTemplateSurveySpec(GenericAPIView):
         if not feature_enabled('surveys'):
             raise LicenseForbids(_('Your license does not allow '
                                    'adding surveys.'))
-        survey_spec = obj.survey_spec
-        for pos, field in enumerate(survey_spec.get('spec', [])):
-            if field.get('type') == 'password':
-                if 'default' in field and field['default']:
-                    field['default'] = '$encrypted$'
 
-        return Response(survey_spec)
+        return Response(obj.display_survey_spec())
 
     def post(self, request, *args, **kwargs):
         obj = self.get_object()