title: ion-select ngModel not being update with ionic 4
body: <p>My app is deployed with Ionic 3 and now i’m into the process of migrating to Ionic 4.</p>
  
  <p>One problem im having with Ionic 4 is with the ion-select using ngModel and ngModelChange,
  it seems when i select one option the ngModel isn't updated so the ngModelChange isn't dispatched.</p>
  
  <p>My code:</p>
  
  <pre><code>&lt;ion-item&gt;
      &lt;ion-label floating&gt;{{ 'Model' | translate }}&lt;/ion-label&gt;
      &lt;ion-select name="model" [(ngModel)]="device.model" (ngModelChange)="updateFirmwareList()" [disabled]="!isNew"
                required #model="ngModel" [cancelText]="ionSelecNameCancel" [okText]="ionSelecNameOk" ngDefaultControl&gt;
                &lt;ion-select-option *ngFor="let model of modelList" [value]="model"&gt;{{ model }}&lt;/ion-select-option&gt;
      &lt;/ion-select&gt;
  &lt;/ion-item&gt;
  </code></pre>
  
  <ul>
  <li><p>I have already loaded the module FormsModule.</p></li>
  <li><p>No errors are being displayed.</p></li>
  <li><p>Im calling the component from a ModalController.</p></li>
  </ul>