fix(discover) Add another export for the upsell page (#16722)

I forgot to add this export earlier but it is needed for the upsell page
in getsentry.

src/sentry/static/sentry/app/views/events/eventsChart.jsx

@@ -232,7 +232,7 @@ const EventsChartContainer = withGlobalSelection(
 );
 
 export default EventsChartContainer;
-export {EventsChart};
+export {EventsChart, EventsAreaChart};
 
 const TransparentLoadingMask = styled(LoadingMask)`
   ${p => !p.visible && 'display: none;'};