Fix sample build and add CI config

Author: guimafelipe

Samples/MultiHeadedPackage/cs/cs-wpf-sparse/PrimaryApp/Assets/SplashScreen.png

@@ -14,10 +14,6 @@
     </AppxManifest>
   </ItemGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Build.Msix" />
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\SecondaryApp\SecondaryApp.csproj" />
   </ItemGroup>

Samples/MultiHeadedPackage/cs/cs-wpf-sparse/PrimaryApp/Assets/Square150x150Logo.png

@@ -16,6 +16,7 @@ parameters:
   - 'Input/cs-winui'
   - 'Installer'
   - 'Mica'
+  - 'MultiHeadedPackage'
   - 'Notifications'
   - 'PhotoEditor'
   - 'ResourceManagement'

Samples/MultiHeadedPackage/cs/cs-wpf-sparse/PrimaryApp/Assets/Square44x44Logo.png

@@ -0,0 +1,7 @@
+# Please see https://www.osgwiki.com/wiki/Windows_App_SDK_-_How_to_build_and_use_the_pipelines
+# for information on how to use the pipelines
+name: $(BuildDefinitionName)_$(date:yyMM).$(date:dd)$(rev:rrr)
+stages:
+- template: WindowsAppSDK-SamplesCI.yml
+  parameters:
+    FeatureDirectory: "MultiHeadedPackage"