title: ionic/angular FileReader error (addEventListener is not a function) occurs in ios simulator
body: <p>I have the function below and it works fine with ionic serve, but i get "reader.addEventListener is not a function" when I'm trying to run the same code on ios simulator.
  Could you help me, please, find out what is wrong?</p>
  
  <pre><code>createImageFromBlob(image: Blob) {
      let reader = new FileReader();
      reader.addEventListener(
        "load",
        () =&gt; {
          this.imageToShow = reader.result;
        },
        false
      );
      if (image) {
        reader.readAsDataURL(image);
      };
    };
  </code></pre>