Improve selection color of datatable

Summary:
DataTable selected rows are a bit hard to spot when changing search, scrolling etc, so give them a bit more prominent background

Changelog: DataTable: more pronounced background color for selections

Reviewed By: aigoncharov

Differential Revision: D36736495

fbshipit-source-id: 2cab9eb99594ffaaccdd9ebe0d922691adb27bdc

desktop/flipper-plugin/src/ui/data-table/TableRow.tsx

@@ -26,7 +26,7 @@ type TableBodyRowContainerProps = {
 
 const backgroundColor = (props: TableBodyRowContainerProps) => {
   if (props.highlighted) {
-    return theme.backgroundWash;
+    return theme.selectionBackgroundColor;
   }
   return undefined;
 };