title: Async function with Firestore does not load my data
body: <p>on my page on <code>nOnInit</code> I use a async function to load some data from firebase (normally the async function wait to get all the data from firebase), so this work correctly and I got my data inside my object <code>getDocu</code></p>
  
  <pre class="lang-js prettyprint-override"><code>async ngOnInit() {
      this.getDocu = await this.Help.getLastTime('JOURNALIER', 'Le Mat', 'lastTime', 'lastTime');
      this.loadItems();
  }
  </code></pre>
  
  <p>Then, inside this page, the user fill in some questions and I am saving the results inside the same document (update) in firebase and when I come back on the page I run <code>ionViewWillEnter</code> to reload the updated data and display it on my page. </p>
  
  <pre class="lang-js prettyprint-override"><code>async ionViewWillEnter() {
      this.getDocu = await this.Help.getLastTime('JOURNALIER', 'Le Mat', 'lastTime', 'lastTime');
      this.loadItems();
  } 
  </code></pre>
  
  <p>Here is my <code>getLastTime</code> function : </p>
  
  <pre class="lang-js prettyprint-override"><code>async getLastTime(collectionName: string, user: string, collec: string, docu: string) {
      const docRef = this.afs.firestore.collection(collectionName).doc(user).collection(collec).doc(docu);
      const doc = await docRef.get();
      if (doc.exists) {
              this.getDocu = doc.data();
          } else {
              this.getDocu = 'Never done';
          }
      return this.getDocu;
    }
  </code></pre>
  
  <p>But when I console log the result of <code>ionViewWillEnter</code>, I do not load the updated data, or if I reload the page manually, this time this is <code>ngOnInit</code> that runs and got the updated value... </p>
  
  <p>Very strange to me, since it looks like I use the same method to get the value... with different results.. </p>