fix aggregator sample warnings

Author: Qiutong Shen

build/NuSpecs/WindowsAppSDK-Nuget-Native.AutoInitializer.targets

@@ -4,7 +4,8 @@
 
   <Target Name="WindowsAppRuntimeAutoInitializer">
     <ItemGroup>
-      <ClCompile Include="$(MSBuildThisFileDirectory)..\..\include\WindowsAppRuntimeAutoInitializer.cpp">
+      <ClCompile 
+        Include="$(MSBuildThisFileDirectory)..\..\include\WindowsAppRuntimeAutoInitializer.cpp" Condition="'@(ClCompile->AnyHaveMetadataValue('Identity', '$(MSBuildThisFileDirectory)..\..\include\WindowsAppRuntimeAutoInitializer.cpp'))' == 'false'">
         <PrecompiledHeader>NotUsing</PrecompiledHeader>
         <PreprocessorDefinitions Condition="'$(WindowsAppSdkBootstrapInitialize)'=='true'">MICROSOFT_WINDOWSAPPSDK_AUTOINITIALIZE_BOOTSTRAP;%(PreprocessorDefinitions)</PreprocessorDefinitions>
         <PreprocessorDefinitions Condition="'$(WindowsAppSdkDeploymentManagerInitialize)'=='true'">MICROSOFT_WINDOWSAPPSDK_AUTOINITIALIZE_DEPLOYMENTMANAGER;%(PreprocessorDefinitions)</PreprocessorDefinitions>