Update howto-device-identity-virtual-desktop-infrastructure.md

Hi we need explicitly mention uniqueness of the device names, as some features will not work without it.

Incident 350657735

Author: alextok

articles/active-directory/devices/howto-device-identity-virtual-desktop-infrastructure.md

@@ -39,6 +39,8 @@ It's important to ensure organizations manage stale devices that are created bec
 > [!IMPORTANT]
 > Failure to manage stale devices can lead to pressure increase on your tenant quota usage consumption and potential risk of service interruption, if you run out of tenant quota. You should follow the guidance documented below when deploying non persistent VDI environments to avoid this situation.
 
+For successful execution of some scenarios, it is important to have unique device names in the directory. It can be achieved by proper management of stale device, or guarantee device name uniqueness, by using some pattern in the device naming.
+
 This article will cover Microsoft's guidance to administrators on support for device identity and VDI. For more information about device identity, see the article [What is a device identity](overview.md).
 
 ## Supported scenarios