title: Firebase custom event parameters not visible in console
body: <p>I need help with custom parameters of Firebase event, don’t seem to be able to see or use any event parameter.
  Basically trying to use parameters to create Audience segmentation, but parameters seem to never arrive (on the other hand all custom events arrive correctly).</p>
  
  <p>As you can see from the attached screenshot the parameters list is always empty for custom events.
  The only parameters we can correctly see are related to system events (like <code>first_open</code> or <code>in_app_purchase</code>).</p>
  
  <p>This is how we trigger custom events and parameters:</p>
  
  <pre><code>FIRAnalytics.logEvent(withName: "game_played", parameters:[
                  "username": "id-\(self.username)" as NSObject,
                  "gameplayed": self._gamePlayed as NSObject
                  ])
  </code></pre>
  
  <p>Any help would really be appreciated.</p>
  
  <p>Firebase console
  <img src="https://i.stack.imgur.com/YeumP.png" alt="Firebase console"></p>