title: How to prevent history state change with back button in modal
body: <p>When I click the Android back button my popup should close. It is not closing. Popup should not appear. I have to override the android back button action.</p>
  
  <pre><code>$ionicPopup.show({
      templateUrl: 'templates/time-picker-12-hour.html',
      title: '&lt;strong&gt;12-Hour Format&lt;/strong&gt;',
      subTitle: '',
      scope: scope,
      buttons: [{
          text: 'Cancel'
      }, {
          text: 'Set',
          type: 'button-assertive',
          onTap: function (e) {
  
              scope.loadingContent = true;
  
              var totalSec = 0;
  
              if (scope.time.hours != 12) {
                  totalSec = (scope.time.hours * 60 * 60) + (scope.time.minutes * 60);
              } else {
                  totalSec = scope.time.minutes * 60;
              }
  
              if (scope.time.meridian === "AM") {
                  totalSec += 0;
              } else if (scope.time.meridian === "PM") {
                  totalSec += 43200;
              }
              scope.etime = totalSec;
          }
      }]
  })
  </code></pre>