Removed preview banner; feature is GA

Author: phecke

powerapps-docs/developer/model-driven-apps/clientapi/reference/Xrm-App/addGlobalNotification.md

@@ -13,13 +13,8 @@ search.app:
 ---
 # addGlobalNotification (Client API reference)
 
-[This topic is pre-release documentation and is subject to change.]
-
 [!INCLUDE[./includes/addGlobalNotification-description.md](./includes/addGlobalNotification-description.md)]
 
-> [!NOTE]
-> This is a preview feature, and is supported only on Unified Interface.
-
 ## Syntax
 
 `Xrm.App.addGlobalNotification(notification).then(successCallback, errorCallback);`