test(CommandBar): add native style manual test

src/SamplesApp/UITests.Shared/UITests.Shared.projitems

@@ -1266,6 +1266,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\CommandBar\CommandBar_Native_With_AppBarButton_Binding.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\IconSourceTests\IconSourceElementTests.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -2905,7 +2909,7 @@
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\ContentControlTestsControl\ContentControl_ComboBoxSetNull.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
-    </Page>    
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\ContentControlTestsControl\ContentControl_FindName.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -5693,6 +5697,9 @@
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\BorderTests\BorderWithNullBrushAndNonZeroThickness.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\BorderTests\PanelWithNullBrushAndNonZeroThickness.xaml.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\CommandBar\CommandBar_Native_With_AppBarButton_Binding.xaml.cs">
+      <DependentUpon>CommandBar_Native_With_AppBarButton_Binding.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\ImageTests\ImageSourceWriteableBitmapInvalidate_Stretch.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\IconSourceTests\IconSourceElementTests.xaml.cs">
       <DependentUpon>IconSourceElementTests.xaml</DependentUpon>
@@ -8923,6 +8930,7 @@
     <Content Include="$(MSBuildThisFileDirectory)Assets\cart.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\check.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\CheckBox.png" />
+    <Content Include="$(MSBuildThisFileDirectory)Assets\closeIcon.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\colored-ellipse.jpg" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\ColorPicker.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\colors300.png" />
@@ -8934,6 +8942,7 @@
     <Content Include="$(MSBuildThisFileDirectory)Assets\Diagnostics\exclamation.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\Diagnostics\movie_type_dbox.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\DropdownButton.png" />
+    <Content Include="$(MSBuildThisFileDirectory)Assets\filter.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\FlipView.png" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\Fonts\Even Badder Mofo.ttf" />
     <Content Include="$(MSBuildThisFileDirectory)Assets\Fonts\FamilyGuy-4grW.ttf" />
@@ -9088,4 +9097,4 @@
     <Content Include="$(MSBuildThisFileDirectory)Assets\libre-camera-panorama.svg" />
   </ItemGroup>
   <Import Project="ItemExclusions.props" />
-</Project>
+</Project>
\ No newline at end of file

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/CommandBar/CommandBarViewModel.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows.Input;
 using Uno.UI.Samples.UITests.Helpers;
 using Windows.UI.Core;
 
@@ -12,12 +13,15 @@ namespace Uno.UI.Samples.Presentation.SamplePages
 		private string _dynamicTitle;
 		private string _dynamicSubTitle1;
 		private string _dynamicSubTitle2;
+		private bool _isChecked;
 
 		public CommandBarViewModel(CoreDispatcher dispatcher) : base(dispatcher)
 		{
+			ToggleChecked = GetOrCreateCommand(() => IsChecked = !IsChecked);
 			StartData();
 		}
 
+		public ICommand ToggleChecked { get; }
 
 		private async void StartData()
 		{
@@ -59,5 +63,15 @@ namespace Uno.UI.Samples.Presentation.SamplePages
 				_dynamicSubTitle2 = value; RaisePropertyChanged();
 			}
 		}
+
+		public bool IsChecked
+		{
+			get { return _isChecked; }
+			set
+			{
+				_isChecked = value;
+				RaisePropertyChanged();
+			}
+		}
 	}
 }

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/CommandBar/CommandBar_Native_With_AppBarButton_Binding.xaml

+<Page
+    x:Class="UITests.Windows_UI_Xaml_Controls.CommandBar.CommandBar_Native_With_AppBarButton_Binding"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:UITests.Windows_UI_Xaml_Controls.CommandBar"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:xamarin="http://nventive.com/xamarin"
+	xmlns:ios="http://nventive.com/ios"
+	xmlns:android="http://nventive.com/android"	
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d xamarin ios android"
+    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+
+	<Page.Resources>
+		<Style x:Name="NativeCommandbarStyle"
+			   TargetType="CommandBar"
+			   xamarin:BasedOn="{StaticResource NativeDefaultCommandBar}">
+			<Setter Property="Background"
+					Value="Blue" />
+			<Setter Property="Foreground"
+					Value="White" />
+		</Style>
+
+		<local:FromNullableBoolToCustomValueConverter x:Key="IsCheckedToIcon"
+													  TrueValue="ms-appx:///Assets/closeIcon.png"
+													  NullOrFalseValue="ms-appx:///Assets/filter.png" />
+	</Page.Resources>
+
+	<StackPanel Background="White">
+		<xamarin:Grid>
+			<CommandBar Content="CommandBar with DataContext Set"
+						Style="{StaticResource NativeCommandbarStyle}"
+						Grid.Row="0">
+				<CommandBar.PrimaryCommands>
+					<AppBarButton Command="{Binding [ToggleChecked]}"
+								  Label="Order"
+								  Foreground="White">
+						<AppBarButton.Icon>
+							<BitmapIcon ShowAsMonochrome="True"
+										UriSource="{Binding [IsChecked], Converter={StaticResource IsCheckedToIcon}}" />
+						</AppBarButton.Icon>
+					</AppBarButton>
+				</CommandBar.PrimaryCommands>
+			</CommandBar>
+		</xamarin:Grid>
+	</StackPanel>
+</Page>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/CommandBar/CommandBar_Native_With_AppBarButton_Binding.xaml.cs

+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Uno.UI.Samples.Controls;
+using Uno.UI.Samples.Presentation.SamplePages;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=234238
+
+namespace UITests.Windows_UI_Xaml_Controls.CommandBar
+{
+
+	[SampleControlInfo("CommandBar", "Native_AppBarButton_Binding", typeof(CommandBarViewModel), isManualTest: true)]
+	public sealed partial class CommandBar_Native_With_AppBarButton_Binding : Page
+	{
+		public CommandBar_Native_With_AppBarButton_Binding()
+		{
+			this.InitializeComponent();
+		}
+	}
+
+	public class FromNullableBoolToCustomValueConverter : IValueConverter
+	{
+		public object NullOrFalseValue { get; set; }
+
+		public object TrueValue { get; set; }
+
+		public object Convert(object value, Type targetType, object parameter, string language)
+		{
+			if (parameter != null)
+			{
+				throw new ArgumentException($"This converter does not use any parameters. You should remove \"{parameter}\" passed as parameter.");
+			}
+
+			if (value != null && !(value is bool))
+			{
+				throw new ArgumentException($"Value must either be null or of type bool. Got {value} ({value.GetType().FullName})");
+			}
+
+			if (value == null || !System.Convert.ToBoolean(value, CultureInfo.InvariantCulture))
+			{
+				return NullOrFalseValue;
+			}
+			else
+			{
+				return TrueValue;
+			}
+		}
+
+		public object ConvertBack(object value, Type targetType, object parameter, string language)
+		{
+			if (parameter != null)
+			{
+				throw new ArgumentException($"This converter does not use any parameters. You should remove \"{parameter}\" passed as parameter.");
+			}
+
+			if (object.Equals(this.TrueValue, this.NullOrFalseValue))
+			{
+				throw new InvalidOperationException("Cannot convert back if both custom values are the same");
+			}
+
+			return this.TrueValue != null ?
+				value.Equals(TrueValue) :
+				!value.Equals(this.NullOrFalseValue);
+		}
+	}
+}