Adding the service principle connection for automation account in azure

 $connectionName = "AzureRunAsConnection"
        $global:servicePrincipalConnection = Get-AutomationConnection -Name $connectionName
        Add-AzureRmAccount `
            -ServicePrincipal `
            -TenantId $servicePrincipalConnection.TenantId `
            -ApplicationId $servicePrincipalConnection.ApplicationId `
        -CertificateThumbprint $servicePrincipalConnection.CertificateThumbprint | Write-Verbose