unblock AltGr+Oem2/5 typing in listbox (#7729)

Co-authored-by: Nmiloush <miloush@users.noreply.github.com>

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Controls/ListBox.cs

@@ -319,7 +319,7 @@ protected override void OnKeyDown(KeyEventArgs e)
                 case Key.Divide:
                 case Key.Oem2:
                     // Ctrl-Fowardslash = Select All
-                    if (((Keyboard.Modifiers & ModifierKeys.Control) == (ModifierKeys.Control)) && (SelectionMode == SelectionMode.Extended))
+                    if (((Keyboard.Modifiers) == (ModifierKeys.Control)) && (SelectionMode == SelectionMode.Extended))
                     {
                         SelectAll();
                     }
@@ -332,7 +332,7 @@ protected override void OnKeyDown(KeyEventArgs e)
 
                 case Key.Oem5:
                     // Ctrl-Backslash = Select the item with focus.
-                    if (((Keyboard.Modifiers & ModifierKeys.Control) == (ModifierKeys.Control)) && (SelectionMode == SelectionMode.Extended))
+                    if (((Keyboard.Modifiers) == (ModifierKeys.Control)) && (SelectionMode == SelectionMode.Extended))
                     {
                         ListBoxItem focusedItemUI = (FocusedInfo != null) ? FocusedInfo.Container as ListBoxItem : null;
                         if (focusedItemUI != null)