change the documentation of bottom navigation bar (#67218)

diff --git a/packages/flutter/lib/src/widgets/bottom_navigation_bar_item.dart b/packages/flutter/lib/src/widgets/bottom_navigation_bar_item.dart
index 00e3c5d..7b41870 100644
--- a/packages/flutter/lib/src/widgets/bottom_navigation_bar_item.dart
+++ b/packages/flutter/lib/src/widgets/bottom_navigation_bar_item.dart
@@ -21,7 +21,7 @@
 class BottomNavigationBarItem {
   /// Creates an item that is used with [BottomNavigationBar.items].
   ///
-  /// The argument [icon] should not be null and the argument [title] should not be null when used in a Material Design's [BottomNavigationBar].
+  /// The argument [icon] should not be null and the argument [label] should not be null when used in a Material Design's [BottomNavigationBar].
   const BottomNavigationBarItem({
     required this.icon,
     @Deprecated(