Merge pull request microsoft#5139 from kasaxena5/AADApplicationKeyCre…

…dentials

AAD Application Keycredentials

Modules/Microsoft365DSC/DSCResources/MSFT_AADApplication/MSFT_AADApplication.psm1

@@ -933,7 +933,16 @@ function Set-TargetResource
 
     if($needToUpdateKeyCredentials -and $KeyCredentials)
     {
-        Write-Warning -Message "KeyCredentials is a readonly property and cannot be configured."
+        Write-Verbose -Message "Updating for Azure AD Application {$($currentAADApp.DisplayName)} with KeyCredentials:`r`n$($KeyCredentials| Out-String)"
+
+        if((currentAADApp.KeyCredentials.Length -eq 0 -and $KeyCredentials.Length -eq 1) -or (currentAADApp.KeyCredentials.Length -eq 1 -and $KeyCredentials.Length -eq 0))
+        {
+            Update-MgApplication -ApplicationId $currentAADApp.Id -KeyCredentials $KeyCredentials | Out-Null
+        }
+        else
+        {
+            Write-Warning -Message "KeyCredentials cannot be updated for AAD Applications with more than one KeyCredentials due to technical limitation of Update-MgApplication Cmdlet. Learn more at: https://learn.microsoft.com/en-us/graph/api/application-addkey"
+        }
     }
 }