[TIMOB-24637] Windows Hyperloop: accessing generic collections throws exception

var MessageDialog = require('Windows.UI.Popups.MessageDialog'),
    UICommand = require('Windows.UI.Popups.UICommand'),
    PropertyValue = require('Windows.Foundation.PropertyValue'),
    Int32 = require('System.Int32');

var dialog = new MessageDialog('My Message');
dialog.Title = 'My Title';
dialog.DefaultCommandIndex = 0;
dialog.Commands.Add(new UICommand('OK', null, PropertyValue.CreateInt32(0)));
dialog.Commands.Add(new UICommand('Cancel', null, PropertyValue.CreateInt32(1)));
dialog.ShowAsync().then(function (command) {
        var id = Int32.cast(command.Id);
        alert((id == 0) ? 'Pushed "OK"' : 'Pushed "Cancel"')
});