Merge pull request #14386 from grafana/explore-fix-interval-update

Explore: graphInterval needs to update after query execution 

public/app/features/explore/Explore.tsx

@@ -654,6 +654,7 @@ export class Explore extends React.PureComponent<ExploreProps, ExploreState> {
         ...results,
         queryTransactions: nextQueryTransactions,
         showingStartPage: false,
+        graphInterval: queryOptions.intervalMs,
       };
     });