title: Reopen my Flutter app in background on FCM message
body: <p>all day I already despair of a waking up system for my VoIP app. I must have already read over 100 articles and documentation about it, however I have not found a solution that works for me.</p>
  <p><strong>Use case:</strong></p>
  <p>My app is running in the background. That means the home button was pressed
  after my app was started and the device is in the home screen. As soon as a notification arrives, the app is supposed to open again on a certain route because a call is coming in.</p>
  <p>In the lock screen I managed this pretty easily with flutter_local_notifications and within the app it was of course no problem either.</p>
  <p><strong>Note:</strong></p>
  <ul>
  <li>Only Android is important, the rest can be neglected</li>
  <li>Android version 10+</li>
  <li>Flutter version 2+</li>
  </ul>
  <p>I appreciate any input on how to solve my problem and have a good week.</p>
  <p>Kind regards,</p>
  <p>Shiro</p>