correct powershell script output

This corrects a bug in the powershell script where the Application Object Id was being displayed as the Application Id causing confusion while setting up AAD integration with webhooks.
Additionally, the formatting of the output section was cleaned up.

Author: dominicdejacomo

articles/event-grid/secure-webhook-delivery.md

@@ -99,10 +99,10 @@ else
     
 New-AzureADServiceAppRoleAssignment -Id $myApp.AppRoles[0].Id -ResourceId $myServicePrincipal.ObjectId -ObjectId $eventGridSP.ObjectId -PrincipalId $eventGridSP.ObjectId
     
-Write-Host "My Azure AD Tenant Id" + $myTenantId
-Write-Host "My Azure AD Application Id" + $myAzureADApplicationObjectId
-Write-Host "My Azure AD Application ($myApp.ObjectId): " + $myApp.ObjectId
-Write-Host "My Azure AD Application's Roles"
+Write-Host "My Azure AD Tenant Id: $myTenantId"
+Write-Host "My Azure AD Application Id: $($myApp.AppId)"
+Write-Host "My Azure AD Application ObjectId: $($myApp.ObjectId)"
+Write-Host "My Azure AD Application's Roles: "
 Write-Host $myApp.AppRoles
 ```