Update description for BusyOnBusyEnabledType

As userOverride option is going to be rolled out in general, updating the description for the parameter

Author: xinawang

skype/skype-ps/skype/Set-CsTeamsCallingPolicy.md

@@ -261,7 +261,7 @@ Accept wildcard characters: False
 ```
 
 ### -BusyOnBusyEnabledType
-Setting this parameter lets you configure how incoming calls are handled when a user is already in a call or conference or has a call placed on hold. Valid options are: Enabled, Unanswered, and Disabled. When set to Enabled, new or incoming calls will be rejected with a busy signal. When set to Unanswered, the user's unanswered settings will take effect, such as routing to voicemail or forwarding to another user. Note: The UserOverride option value is not available for use currently, if set it will be read as setting the value to Disabled.
+Setting this parameter lets you configure how incoming calls are handled when a user is already in a call or conference or has a call placed on hold. Valid options are: Enabled, Unanswered Disabled, UserOverride. When set to Enabled, new or incoming calls will be rejected with a busy signal. When set to Unanswered, the user's unanswered settings will take effect, such as routing to voicemail or forwarding to another user. Set this to UserOverride to allow users to directly set their busy options from Calls settings in Teams app. 
 
 ```yaml
 Type: String