Use Managed Identity for APIScan authentication (PowerShell#24243)

Co-authored-by: Travis Plunk <[email protected]>

Author: adityapatwardhan

tools/releaseBuild/azureDevOps/templates/compliance/apiscan.yml

@@ -148,7 +148,7 @@ jobs:
         # write a status update every 5 minutes.  Default is 1 minute
         statusUpdateInterval: '00:05:00'
       env:
-        AzureServicesAuthConnectionString: RunAs=App;AppId=$(APIScanClient);TenantId=$(APIScanTenant);AppKey=$(APIScanSecret)
+        AzureServicesAuthConnectionString: RunAs=App
 
     - task: securedevelopmentteam.vss-secure-development-tools.build-task-report.SdtReport@2
       continueOnError: true