notif [nfc]: Add TODO-android comment on autoCancel workaround

Author: gnprice

lib/notifications/display.dart

@@ -158,9 +158,11 @@ class NotificationDisplayManager {
       inboxStyle: InboxStyle(
         // TODO(#570) Show organization name, not URL
         summaryText: data.realmUri.toString()),
+
       // On Android 11 and lower, if autoCancel is not specified,
       // the summary notification may linger even after all child
       // notifications have been opened and cleared.
+      // TODO(android-12): cut this autoCancel workaround
       autoCancel: true,
     );
   }