Fixed casing: "Powershell" -> "PowerShell" (#13080)
Fixed casing: "Powershell" -> "PowerShell" (#13080)

Co-authored-by: Bishal Prasad <f9a8f3a37a38e07b9217a249c2c3ee0cfa720e29@microsoft.com>
Microsoft/vsts-tasks,Microsoft/vso-agent-tasks,Microsoft/vso-agent-tasks,Microsoft/vso-agent-tasks,Microsoft/vsts-tasks,Microsoft/vsts-tasks,Microsoft/vsts-tasks,Microsoft/vsts-tasks