Update private-endpoint-dns.md

Added missing zones from IoT Central. 
When provisioning this PE, generates entries in four different zones:
[resource_subdomain].azureiotcentral.com ->
[resource_subdomain].privatelink.azureiotcentral.com

iotc-[guid1].azure-devices.net ->
iotc-[guid1].privatelink.azure-devices.net

iothub-ns-iotc-[...].servicebus.windows.net ->
iothub-ns-iotc-[...].privatelink.servicebus.windows.net

saas-dps-[guid2].azure-devices-provisioning.net ->
saas-dps-[guid2].privatelink.azure-devices-provisioning.net

Author: juanandmsft

articles/private-link/private-endpoint-dns.md

@@ -154,7 +154,7 @@ For Azure services, use the recommended zone names as described in the following
 >| Azure IoT Hub (Microsoft.Devices/IotHubs) | iotHub | privatelink.azure-devices.net<br/>privatelink.servicebus.windows.net<sup>1</sup> | azure-devices.net<br/>servicebus.windows.net |
 >| Azure IoT Hub Device Provisioning Service (Microsoft.Devices/ProvisioningServices) | iotDps | privatelink.azure-devices-provisioning.net | azure-devices-provisioning.net |
 >| Device Update for IoT Hubs (Microsoft.DeviceUpdate/accounts) | DeviceUpdate | privatelink.api.adu.microsoft.com | api.adu.microsoft.com |
->| Azure IoT Central (Microsoft.IoTCentral/IoTApps) | iotApp | privatelink.azureiotcentral.com | azureiotcentral.com |
+>| Azure IoT Central (Microsoft.IoTCentral/IoTApps) | iotApp | privatelink.azureiotcentral.com </br> privatelink.azure-devices.net </br> privatelink.servicebus.windows.net </br> privatelink.azure-devices-provisioning.net | azureiotcentral.com </br> privatelink.azure-devices.net </br> privatelink.servicebus.windows.net </br> privatelink.azure-devices-provisioning.net|
 >| Azure Digital Twins (Microsoft.DigitalTwins/digitalTwinsInstances) | API | privatelink.digitaltwins.azure.net | digitaltwins.azure.net |
 
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