Fix group selection state not persisting on PinnedGroupHeader when scrolling

mobile/apps/photos/lib/ui/viewer/gallery/component/group/group_header_widget.dart

@@ -39,6 +39,14 @@ class _GroupHeaderWidgetState extends State<GroupHeaderWidget> {
     widget.selectedFiles?.addListener(_selectedFilesListener);
   }
 
+  @override
+  void didUpdateWidget(covariant GroupHeaderWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.title != widget.title) {
+      _areAllFromGroupSelectedNotifier.value = _areAllFromGroupSelected();
+    }
+  }
+
   @override
   void dispose() {
     _areAllFromGroupSelectedNotifier.dispose();