Initial value of datepicker (angular-ui) isn't shown

<!doctype html>
<html ng-app="ui.bootstrap.demo">
  <head>
    <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.3/angular.js"></script>
    <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.3/angular-animate.js"></script>
    <script src="//angular-ui.github.io/bootstrap/ui-bootstrap-tpls-1.3.3.js"></script>
    <script src="example.js"></script>
    <link href="//netdna.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div ng-controller="DatepickerDemoCtrl">
  {{test2}}
  <br>
  {{symptomsSelected}}
  <pre>Selected date is: 
    <em>{{tournament.startDate | date:'fullDate' }}</em>
  </pre>
  <input name=startDate" id="startDate" type="text" class="form-control" uib-datepicker-popup="{{format}}" ng-model="tournament.startDate" is-open="popup1.opened"
         ng-required="true" close-text="Schließen""
         datepicker-options="dateOptions" alt-input-formats="altInputFormats" />
  <span class="input-group-btn">
      <button type="button" class="btn btn-default" ng-click="open1()"><i class="glyphicon glyphicon-calendar"></i></button>
  </span>
</div>
</body>
</html>

angular.module('ui.bootstrap.demo', ['ngAnimate', 'ui.bootstrap']);
angular.module('ui.bootstrap.demo').controller('DatepickerDemoCtrl', function ($scope) {


$scope.symptomsSelected="["+'"\My selected item is string\"'+"]"
$scope.test2 =angular.fromJson($scope.symptomsSelected);
$scope.test2=$scope.test2[0];






    $scope.dateOptions = {
        dateDisabled: false,
        formatYear: 'yy',
        maxDate: new Date(2020, 5, 22),
        minDate: new Date(),
        startingDay: 1
    };
    
    $scope.tournament = {};
    $scope.tournament.startDate = new Date();
    
    $scope.popup1 = {
     opened: false
   };
    
    $scope.open1 = function() {
      $scope.popup1.opened = true;
    };
});