Pass extraData to stickyOverrideRowRenderer to re-render sticky h…

…eaders

In our usage of FlashList we have a "selected" checkbox on the sticky header of each group. 

When these rows are stuck to the top, they don't update when `extraData` changes. When they come unstuck from the top, they update immediately. Regular header rows are updated when `extraData` changes, but these for some reason aren't.

We've been testing this locally and it works nicely. I don't know whether there's a specific reason that `extraData` is not included in sticky row renderers, but it seems reasonable that rows should behave the same way when they're stuck as they do when they're not stuck.

src/FlashList.tsx

@@ -695,14 +695,15 @@ class FlashList<T> extends React.PureComponent<
     _: any,
     __: any,
     index: number,
-    ___: any
+    extraData: any
   ) => {
     return (
       <PureComponentWrapper
         ref={this.stickyContentRef}
         enabled={this.isStickyEnabled}
         arg={index}
         renderer={this.rowRendererSticky}
+        extraData={extraData}
       />
     );
   };