[main] Update common Docker engineering infrastructure with latest (#677

)

Update common Docker engineering infrastructure with latest

eng/common/templates/jobs/build-images.yml

@@ -129,11 +129,20 @@ jobs:
     - powershell: |
         $images = "$(BuildImages.builtImages)"
         if (-not $images) { return 0 }
-        $taskDir = $(Get-ChildItem -Recurse -Directory -Filter "ManifestGeneratorTask*" -Path '$(Agent.WorkFolder)').FullName
+        # There can be leftover versions of the task left on the agent if it's not fresh. So find the latest version.
+        $taskDir = $(Get-ChildItem -Recurse -Directory -Filter "ManifestGeneratorTask*" -Path '$(Agent.WorkFolder)')[-1].FullName
         $manifestToolDllPath = $(Get-ChildItem -Recurse -File -Filter "Microsoft.ManifestTool.dll" -Path $taskDir).FullName
-        $dotnetDir = $(Get-ChildItem -Recurse -Directory -Filter "*dotnet-*" -Path "$(Agent.ToolsDirectory)").FullName
 
-        # If the manifest tool installed its own version of .NET use that; otherwise it's reusing an existing install of .NET
+        # Check whether the manifest task installed its own version of .NET.
+        # To be more robust, we'll handle varying implementations that it's had.
+        # First check for a dotnet folder in the task location
+        $dotnetDir = $(Get-ChildItem -Recurse -Directory -Filter "dotnet-*" -Path $taskDir).FullName
+        if (-not $dotnetDir) {
+          # If it's not there, check in the agent tools location
+          $dotnetDir = $(Get-ChildItem -Recurse -Directory -Filter "*dotnet-*" -Path "$(Agent.ToolsDirectory)").FullName
+        }
+
+        # If the manifest task installed its own version of .NET use that; otherwise it's reusing an existing install of .NET
         # which is executable by default.
         if ($dotnetDir) {
           $dotnetPath = "$dotnetDir/dotnet"