Update to WASDK2.0

WinUIGallery/ContentIncludes.props

@@ -238,6 +238,9 @@
     <Content Include="Samples\SampleCode\SystemBackdrops\SystemBackdropsSampleBackdropTypes_xaml.txt" />
     <Content Include="Samples\SampleCode\SystemBackdrops\SystemBackdropsSampleMicaController.txt" />
     <Content Include="Samples\SampleCode\SystemBackdrops\SystemBackdropsSampleDesktopAcrylicController.txt" />
+    <Content Include="Samples\SampleCode\SystemBackdropElement\SystemBackdropElementAcrylic_xaml.txt" />
+    <Content Include="Samples\SampleCode\SystemBackdropElement\SystemBackdropElementMica_xaml.txt" />
+    <Content Include="Samples\SampleCode\SystemBackdropElement\SystemBackdropElementMicaAlt_xaml.txt" />
     <Content Include="Samples\SampleCode\TabView\TabViewBasicSample_cs.txt" />
     <Content Include="Samples\SampleCode\TabView\TabViewKeyboardAcceleratorSample_cs.txt" />
     <Content Include="Samples\SampleCode\TeachingTip\TeachingTipSample2_xaml.txt" />

WinUIGallery/Controls/PageHeader.xaml

@@ -260,18 +260,6 @@
                         </TeachingTip>
                     </local:CopyButton.Resources>
                 </local:CopyButton>
-                <Button
-                    x:Name="FeedbackBtn"
-                    Height="32"
-                    Margin="0,0,4,0"
-                    AutomationProperties.Name="Send feedback"
-                    Click="OnFeedBackButtonClick"
-                    ToolTipService.ToolTip="Send feedback">
-                    <Button.Content>
-                        <FontIcon FontSize="16" Glyph="&#xED15;" />
-                    </Button.Content>
-                </Button>
-                <AppBarSeparator />
                 <ToggleButton
                     x:Name="FavoriteButton"
                     Height="32"

WinUIGallery/Controls/PageHeader.xaml.cs

@@ -107,10 +107,6 @@ private void OnCopyLink()
 
         ProtocolActivationClipboardHelper.Copy(this.Item);
     }
-    public async void OnFeedBackButtonClick(object sender, RoutedEventArgs e)
-    {
-        await Windows.System.Launcher.LaunchUriAsync(new Uri("https://github.com/microsoft/WinUI-Gallery/issues/new/choose"));
-    }
 
     private void UserControl_Loaded(object sender, RoutedEventArgs e)
     {