PowerShell correction (SharePoint#2826)

Correct the PowerShell given in the "Generate a report that lists each add-in and the date that its secret expires..." step. The current script simply outputs a static date (today) instead of the expiration date of the secret.

Author: paulewert

docs/sp-add-ins/replace-an-expiring-client-secret-in-a-sharepoint-add-in.md

@@ -41,19 +41,14 @@ Ensure the following before you begin:
   - From the remainder, it filters out non-SharePoint add-ins and add-ins that use asymmetric keys, such as workflows.
 
   ```powershell
-    $applist = Get-MsolServicePrincipal -all  |Where-Object -FilterScript { ($_.DisplayName -notlike "*Microsoft*") -and ($_.DisplayName -notlike "autohost*") -and  ($_.ServicePrincipalNames -notlike "*localhost*") }
+$applist = Get-MsolServicePrincipal -all  |Where-Object -FilterScript { ($_.DisplayName -notlike "*Microsoft*") -and ($_.DisplayName -notlike "autohost*") -and  ($_.ServicePrincipalNames -notlike "*localhost*") }
 
-  foreach ($appentry in $applist)
-  {
-      $principalId = $appentry.AppPrincipalId
-      $principalName = $appentry.DisplayName
-      
-      Get-MsolServicePrincipalCredential -AppPrincipalId $principalId -ReturnKeyValues $false | Where-Object { ($_.Type -ne "Other") -and ($_.Type -ne "Asymmetric") }
-      
-      $date = get-date
-      Write-Host "$principalName;$principalId;$appentry.KeyId;$appentry.type;$date;$appentry.Usage"
-
-  }  > c:\temp\appsec.txt
+foreach ($appentry in $applist) {
+    $principalId = $appentry.AppPrincipalId
+    $principalName = $appentry.DisplayName
+    
+    Get-MsolServicePrincipalCredential -AppPrincipalId $principalId -ReturnKeyValues $false | ? { $_.Type -eq "Password" } | % { "$principalName;$principalId;" + $_.KeyId.ToString() +";" + $_.StartDate.ToString() + ";" + $_.EndDate.ToString() } | out-file -FilePath c:\temp\appsec.txt -append
+}
   ```
 
 4. Open the file C:\temp\appsec.txt to see the report. Leave the Windows PowerShell window open for the next procedure, if any of the secrets are near expiration.
@@ -180,4 +175,4 @@ For expired client secrets, first you must delete all of the expired secrets for
 
 - [Provider Hosted App fails on SPO](https://blogs.technet.microsoft.com/sharepointdevelopersupport/2015/03/11/provider-hosted-app-fails-on-spo/)
 - [Creating SharePoint Add-ins that use low-trust authorization](creating-sharepoint-add-ins-that-use-low-trust-authorization.md)
-- [Authorization and authentication of SharePoint Add-ins](authorization-and-authentication-of-sharepoint-add-ins.md)
+- [Authorization and authentication of SharePoint Add-ins](authorization-and-authentication-of-sharepoint-add-ins.md)