Added build step to verify agent OS (#4758)

* Added build step to verify agent OS

.azure-pipelines/client.yml

@@ -125,11 +125,23 @@ jobs:
       vmImage: '$(OSVmImage)'
 
     steps:
+      - powershell: |
+            Invoke-WebRequest -Uri "https://github.com/Azure/azure-sdk-tools/releases/download/sdk-tools_14793/sdk-tools.zip" `
+            -OutFile "sdk-tools.zip" | Wait-Process; Expand-Archive -Path "sdk-tools.zip" -DestinationPath "./sdk-tools/"
+        workingDirectory: '$(Build.BinariesDirectory)'
+        displayName: 'Download Tools Archive From Github Release and Extract it'
+
       - task: UsePythonVersion@0
         displayName: 'Use Python $(PythonVersion)'
         inputs:
           versionSpec: '$(PythonVersion)'
 
+      - task: PythonScript@0
+        displayName: 'Run VerifyAgentOS script'
+        inputs:
+          scriptPath: '$(Build.BinariesDirectory)/sdk-tools/scripts/python/verify_agent_os.py'
+          arguments: $(OSName)
+
       - script: |
           pip install pathlib twine codecov beautifulsoup4
         displayName: 'Prep Environment'