title: I cannot enable firestore on a project although I'm not using AppEngine nor Datastore
body: <p>I'm trying to activate firestore on a project on which I'm not using AppEngine nor Datastore and having this error message.</p>
  
  <p><em>Cannot enable Firestore for this project
  Currently Firestore cannot be enabled in projects already using Cloud Datastore or App Engine</em></p>
  
  <p>To be more precise, I used to use datastore but now there is no entities in my project datastore. So maybe there is something that I need to disable explicitly </p>
  
  <p>Thx in advance for your help</p>