Add generation task for Az.Tools.Installer to auto-generate manifest files. (#23892)

Author: vidai-msft

.azure-pipelines/sign-tool-installer.yml

@@ -67,9 +67,15 @@ steps:
     custom: msbuild
     arguments: 'tools\Az.Tools.Installer\build.proj /t:Package /p:Configuration=Release'
 
+- task: ManifestGeneratorTask@0
+  displayName: 'Generation Task'
+    inputs:
+      PackageName: 'Azure PowerShell - Az Tools Installer'
+      BuildDropPath: '$(System.ArtifactsDirectory)/artifacts'
+
 - task: PublishPipelineArtifact@0
   displayName: 'Save artifacts'
   inputs:
     artifactName: artifacts
     targetPath: artifacts
-  condition: succeededOrFailed()
+  condition: succeededOrFailed()