title: Test react native firebase push notification in simulator
body: <p>According to the react native firebase doc, the push notification does not work in simulator.
  Even Out-of-app notifications (when app is in background and you see the notification in the status bar) does not work when you run the app on your real ios/Android device connected to your PC by cable. (In-app notifications work though using <code>messaging().onMessage</code>)</p>
  
  <p><strong>Current behavior</strong>:
  My Firebase push notification works perfectly on both Android and ios in standalone apk/ipa.
  However, I cannot test it during development on simulator.</p>
  
  <p><strong>Desired behavior</strong>:
  I want to receive push notification (Out-of-app notification) when the app is running on simulator in background, so that I can use <code>messaging().onNotificationOpenedApp</code> method as usual.</p>
  
  <p><strong>Why I need this?</strong>
  Of course, each time I make a change regarding push notification, I can create a standalone app, install it on phone to see how it works.
  This approach has many issues:</p>
  
  <ol>
  <li>It's super time-consuming and does not  make sense at all </li>
  <li>If the code does not work as expected, there is no way to check what goes wrong</li>
  <li>There is no <code>console.log</code>, in general, no way to debug the code </li>
  </ol>