fix template variable bug

public/app/plugins/datasource/stackdriver/components/AliasBy.tsx

@@ -22,6 +22,12 @@ export class AliasBy extends Component<Props, State> {
     this.setState({ value: this.props.value });
   }
 
+  componentWillReceiveProps(nextProps: Props) {
+    if (nextProps.value !== this.props.value) {
+      this.setState({ value: nextProps.value });
+    }
+  }
+
   handleChange(e) {
     this.setState({ value: e.target.value });
     this.onChange(e.target.value);

public/app/plugins/datasource/stackdriver/components/Metrics.tsx

@@ -119,7 +119,7 @@ export class Metrics extends React.Component<Props, State> {
   handleMetricTypeChange(value) {
     const metricDescriptor = this.getSelectedMetricDescriptor(value);
     this.setState({ metricDescriptor });
-    this.props.onChange(metricDescriptor);
+    this.props.onChange({ ...metricDescriptor, type: value });
   }
 
   getServicesList(metricDescriptors) {
@@ -170,7 +170,13 @@ export class Metrics extends React.Component<Props, State> {
               onChange={value => this.handleMetricTypeChange(value)}
               value={metricType}
               variables={templateSrv.variables}
-              options={metrics}
+              options={[
+                {
+                  label: 'Metrics',
+                  expanded: true,
+                  options: metrics,
+                },
+              ]}
               placeholder="Select Metric"
               className="width-15"
             />