Fix [Android] CollectionView EmptyView SelectionMode=Single on Android (

#9215) Fixes #9060

* Fixed null reference when we have EmptyView and SelectionMode = signle

* Moved null check out of loop

* Moved adapter null check to the begging of the method

src/Controls/src/Core/Platform/Android/Extensions/RecyclerViewExtensions.cs

@@ -13,7 +13,10 @@ public static void UpdateSelection(this RecyclerView recyclerView, SelectableIte
  var mode = selectableItemsView.SelectionMode;
  //TODO: on NET7 implement a ISelectableItemsViewAdapter interface on the adapter
  var adapter = recyclerView.GetAdapter() as ReorderableItemsViewAdapter<ReorderableItemsView, IGroupableItemsViewSource>;
- adapter?.ClearPlatformSelection();
+ if (adapter == null)
+ return;
+
+ adapter.ClearPlatformSelection();
 
  switch (mode)
  {
@@ -25,13 +28,12 @@ public static void UpdateSelection(this RecyclerView recyclerView, SelectableIte
  adapter.MarkPlatformSelection(selectedItem);
  return;
 
- case SelectionMode.Multiple:
- var selectedItems = selectableItemsView.SelectedItems;
-
- foreach (var item in selectedItems)
- {
- adapter.MarkPlatformSelection(item);
- }
+ case SelectionMode.Multiple: 
+ var selectedItems = selectableItemsView.SelectedItems;
+ foreach (var item in selectedItems)
+ {
+ adapter.MarkPlatformSelection(item);
+ } 
  return;
  }
  }