Add variant and metrics to events_plot mapping

apiserver/elastic/mappings/events/events_plot.json

@@ -9,7 +9,13 @@
       },
       "plot_data": {
         "type": "binary"
+      },
+      "variant": { 
+        "type": "keyword"
+      },
+      "metric": { 
+        "type": "keyword"
       }
     }
   }
-}
+}