title: Ionic change text displayed on ion-select when an option is selected
body: <p>I don't know if you get the idea. What I want to do is having an ion-select with option, and when user selects, for example, "Albania (+355)" and press OK button, in the select will only be displayed "+355" instead of "Albania (+355)"</p>
  
  <p>add-contact.html</p>
  
  <pre><code>      &lt;ion-select [(ngModel)]="selected_value" (ionChange)="getCountry(selected_value)" placeholder="País"&gt;
          &lt;ion-option [value]="countries" *ngFor="let countries of country"&gt;
            {{countries.country_name}} ({{countries.dialling_code}})
          &lt;/ion-option&gt;
        &lt;/ion-select&gt;
  </code></pre>
  
  <p>add-contact.ts</p>
  
  <pre><code>country = [{ "country_code": "AL", "country_name": "Albania","dialling_code": "+355" },
             { "country_code": "DZ", "country_name": "Algeria", "dialling_code":"+213" }];
  </code></pre>
  
  <p>This is what I have:
  <a href="https://i.stack.imgur.com/0BTKl.png" rel="noreferrer">name-code-displayed</a></p>
  
  <p>This is what I try to display: <a href="https://i.stack.imgur.com/ONRqQ.png" rel="noreferrer">only-code-displayed</a></p>