update xcopy msbuild to 17.12.0 (#15248)

Author: riarenas

eng/common/sdk-task.ps1

@@ -64,7 +64,7 @@ try {
       $GlobalJson.tools | Add-Member -Name "vs" -Value (ConvertFrom-Json "{ `"version`": `"16.5`" }") -MemberType NoteProperty
     }
     if( -not ($GlobalJson.tools.PSObject.Properties.Name -match "xcopy-msbuild" )) {
-      $GlobalJson.tools | Add-Member -Name "xcopy-msbuild" -Value "17.10.0-pre.4.0" -MemberType NoteProperty
+      $GlobalJson.tools | Add-Member -Name "xcopy-msbuild" -Value "17.12.0" -MemberType NoteProperty
     }
     if ($GlobalJson.tools."xcopy-msbuild".Trim() -ine "none") {
         $xcopyMSBuildToolsFolder = InitializeXCopyMSBuild $GlobalJson.tools."xcopy-msbuild" -install $true

eng/common/tools.ps1

@@ -383,8 +383,8 @@ function InitializeVisualStudioMSBuild([bool]$install, [object]$vsRequirements =
 
   # If the version of msbuild is going to be xcopied,
   # use this version. Version matches a package here:
-  # https://dev.azure.com/dnceng/public/_artifacts/feed/dotnet-eng/NuGet/Microsoft.DotNet.Arcade.MSBuild.Xcopy/versions/17.10.0-pre.4.0
-  $defaultXCopyMSBuildVersion = '17.10.0-pre.4.0'
+  # https://dev.azure.com/dnceng/public/_artifacts/feed/dotnet-eng/NuGet/Microsoft.DotNet.Arcade.MSBuild.Xcopy/versions/17.12.0
+  $defaultXCopyMSBuildVersion = '17.12.0'
 
   if (!$vsRequirements) {
     if (Get-Member -InputObject $GlobalJson.tools -Name 'vs') {