title: Is the new Firebase messaging server key restricted to messaging?
body: <p>Is the new server key restricted to messaging only?</p>
  
  <p><strong>explanation:</strong>
  In firebase project settings, I can get "old" and new server keys(cloud messaging tab). 
  The old ones don't work to send push notifications via <a href="https://fcm.googleapis.com/fcm/send" rel="nofollow noreferrer">https://fcm.googleapis.com/fcm/send</a> because the response says that it is a legacy server key. But it can be restricted to certain google apis here <a href="https://console.developers.google.com/apis" rel="nofollow noreferrer">https://console.developers.google.com/apis</a>.
  The new is not listed in google apis console, but works. </p>
  
  <p>We want to share the server key with partners, but won't allow to do other stuff. The new HTTP API V1 with OAuth2 is not an option unfortunately. </p>
  
  <p>According to docs:</p>
  
  <blockquote>
    <p>Server key (for legacy protocols): A server key that authorizes your app server for access to Google services, including sending messages via the Firebase Cloud Messaging legacy protocols.</p>
  </blockquote>
  
  <p>Which services are here meant? </p>