notify Voicemail Counter Changed
Invoked when there is a change in the voicemail counter.
This method is called when the count of voicemails has been updated. You can use the provided counter
parameter to obtain the updated voicemail count and take appropriate actions, such as displaying a notification.
Note: This method can be called when the application is launched or in push mode.
Parameters
counter
The updated count of voicemails.