Fixes Comment on #16563: DefaultToolbarMenu registering for bookmark changes

comment link: https://github.com/mozilla-mobile/fenix/pull/16536#discussion_r522387945

app/src/main/java/org/mozilla/fenix/components/toolbar/DefaultToolbarMenu.kt

@@ -133,6 +133,8 @@ class DefaultToolbarMenu(
             }
         )
 
+        registerForIsBookmarkedUpdates()
+
         val bookmark = BrowserMenuItemToolbar.TwoStateButton(
             primaryImageResource = R.drawable.ic_bookmark_filled,
             primaryContentDescription = context.getString(R.string.browser_menu_edit_bookmark),