Correct label for podcast context menu from cancel to close.

Author: amugofjava

lib/ui/podcast/podcast_context_menu.dart

@@ -259,7 +259,7 @@ class _CupertinoContextMenu extends StatelessWidget {
                     onPressed: () {
                       Navigator.pop(context, 'Cancel');
                     },
-                    child: Text(L.of(context)!.cancel_option_label),
+                    child: Text(L.of(context)!.close_button_label),
                   ),
                 );
               },