fix data source picker for alerts card (#1149)

Signed-off-by: Joanne Wang <jowg@amazon.com>
(cherry picked from commit 20b50b5)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

public/components/DataSourceAlertsCard/DataSourceAlertsCard.tsx

@@ -49,7 +49,7 @@ export const DataSourceAlertsCard: React.FC<DataSourceAlertsCardProps> =  ({ get
   }, [dataSource]);
 
   const onDataSourceSelected = useCallback((options: any[]) => {
-    if (dataSource?.id !== undefined && dataSource?.id !== options[0]?.id) {
+    if (dataSource?.id === undefined || dataSource?.id !== options[0]?.id) {
       setDataSource(options[0]);
     }
   }, [dataSource]);