title: Mobile App - Best Approach to switch between Firebase Projects in Authentication
body: <p>We are creating a mobile app that will use Firebase Authentication.
  This app is an app used for enterprise customers who subscribed for the service.
  Our plan in terms of architecture is:
    - have just one app client for all customers
    - create a Firebase project for each customer</p>
  
  <p>In this context, what could be a best approach for app define which Firebase Project login ?
  Do someone has experience with Firebase in Multi tenant environment ?</p>
  
  <p>Regards,</p>