title: FCM 'condition' field does not work
body: <p>I cannot manage to send a FCM message to be sent to multiple topics with the <em>condition</em> field. For some reason, even though FCM does not send my any error, my devices do not receive the message when using this field.</p>
  
  <p>When I send this :</p>
  
  <pre><code>{
  "to": "/topics/topic1",
  "data": {
      "message": "test"
      }
  }
  </code></pre>
  
  <p>the message is received, but I do not receive anything with this :</p>
  
  <pre><code>{
  "condition": "'topic1' in topics",
  "data": {
      "message": "test"
      }
  }
  </code></pre>
  
  <p>even thought both message use the same topic name and both message return a success message from Firebase.</p>