change idle timeout from 30 to 15

Author: vhorne

articles/firewall/firewall-faq.yml

@@ -302,7 +302,7 @@ sections:
 
       - question: What is the TCP Idle Timeout for Azure Firewall?
         answer: |
-          A standard behavior of a network firewall is to ensure TCP connections are kept alive and to promptly close them if there's no activity. Azure Firewall TCP Idle Timeout is four minutes. This setting isn't user configurable, but you can contact Azure Support to increase the Idle Timeout for inbound and outbound connections up to 30 minutes. Idle Timeout for east-west traffic can't be changed.
+          A standard behavior of a network firewall is to ensure TCP connections are kept alive and to promptly close them if there's no activity. Azure Firewall TCP Idle Timeout is four minutes. This setting isn't user configurable, but you can contact Azure Support to increase the Idle Timeout for inbound and outbound connections up to 15 minutes. Idle Timeout for east-west traffic can't be changed.
 
           If a period of inactivity is longer than the timeout value, there's no guarantee that the TCP or HTTP session is maintained. A common practice is to use a TCP keep-alive. This practice keeps the connection active for a longer period. For more information, see the [.NET examples](/dotnet/api/system.net.servicepoint.settcpkeepalive).