Fixed incorrect paths for pipeline sample resources

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/ImageBlendBrush/ImageBlendBrushXaml.bind

@@ -18,7 +18,7 @@
       <Border Grid.Column="0">
         <Border.Background>
           <media:ImageBlendBrush
-            Source="/SamplePages/DropShadowPanel/Unicorn.png"
+            Source="/SamplePages/Shadows/Unicorn.png"
             Stretch="@[Unicorn Stretch:Enum:Stretch.None]"
             Mode="@[Unicorn Blend Mode:Enum:ImageBlendMode.ColorBurn]"
           />

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/PipelineBrush/PipelineBrushXaml.bind

@@ -26,7 +26,7 @@
             <media:BlurEffect Amount="16"/>
             <media:ShadeEffect Color="#FF222222" Intensity="0.2"/>
             <media:BlendEffect Mode="Overlay" Source="{media:TileSource Uri=ms-appx:///Assets/BrushAssets/NoiseTexture.png}"/>
-            <media:BlendEffect Mode="Overlay" Source="{media:ImageSource Uri=ms-appx:///SamplePages/DropShadowPanel/Unicorn.png}"/>
+            <media:BlendEffect Mode="Overlay" Source="{media:ImageSource Uri=ms-appx:///SamplePages/Shadows/Unicorn.png}"/>
           </media:PipelineBrush>
         </Border.Background>
       </Border>

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/VisualEffectFactory/VisualEffectFactory.bind

@@ -25,7 +25,7 @@
             <media:BlurEffect Amount="16"/>
             <media:ShadeEffect Color="#FF222222" Intensity="0.2"/>
             <media:BlendEffect Mode="Overlay" Source="{media:TileSource Uri=ms-appx:///Assets/BrushAssets/NoiseTexture.png}"/>
-            <media:BlendEffect Mode="Overlay" Source="{media:ImageSource Uri=ms-appx:///SamplePages/DropShadowPanel/Unicorn.png}"/>
+            <media:BlendEffect Mode="Overlay" Source="{media:ImageSource Uri=ms-appx:///SamplePages/Shadows/Unicorn.png}"/>
           </media:PipelineVisualFactory>
         </media:UIElementExtensions.VisualFactory>
       </Border>