stackdriver: remove not used code

public/app/plugins/datasource/stackdriver/metricTypes.tsx

@@ -1,5 +1,4 @@
 import React, { SFC } from 'react';
-import uniqBy from 'lodash/uniqBy';
 
 interface Props {
   onMetricTypeChanged: any;
@@ -19,11 +18,6 @@ const MetricTypes: SFC<Props> = props => {
     }));
   };
 
-  uniqBy(props.metricDescriptors, 'service').map(m => ({
-    value: m.service,
-    name: m.serviceShortName,
-  }));
-
   return (
     <div className="gf-form max-width-21">
       <span className="gf-form-label width-7">Metric Types</span>