title: send notification from firebase console to old users with gcm tokens?
body: <p>I have questions about migrating from gcm to fcm.
  we are going to migrate from gcm to fcm. we have lots of users with gcm tokens and we have already sent them push notifications from onesignal panel. now when we migrate to fcm,what happens to old users with gcm tokens? I know if we force our users to update their android version to new version(the one with fcm) the new fcm token will be generated for users. but what if we don't want to force our users to update? Is it possible to send notification from firebase console to old users that have gcm tokens? </p>
  
  <p>I have already done the migration procedure according to this link:
  <a href="https://developers.google.com/cloud-messaging/android/android-migrate-fcm" rel="nofollow noreferrer">https://developers.google.com/cloud-messaging/android/android-migrate-fcm</a></p>