Update Disable-App.md

Confirmed with the PG in below ADO issue that even if admin disabled default app by Disable-App cmdlet, it gets enabled automatically once user access the app thereafter.

https://o365exchange.visualstudio.com/DefaultCollection/O365%20Core/_workitems/edit/5593477

Therefore, mentioning the same to avoid confusion at customer side (There are already similar SRs in the past from time to time).

Author: mshahane

exchange/exchange-ps/ExchangePowerShell/Disable-App.md

@@ -60,6 +60,8 @@ Disable-App -Identity 545d8236-721a-468f-85d8-254eca7cb0da -Mailbox Tony
 
 This example disables the Share to Teams app for user Tony.
 
+**Note**: Even if you disable default app by this cmdlet, it will be enabled automatically when user access respective app. This is by design behavior.
+
 ## PARAMETERS
 
 ### -Identity