callForwarding: Add service class

The service class should be delivered as user input
regarding video call forwarding.
Regarding new interface, the service class value is added.
The service class value is from layout.

Bug: 146531990

Change-Id: I8514f330d6e9689d05ff5e37aaa5799da85fb9a8
Signed-off-by: Jang Hayeong <hayeong.jang@samsung.com>
3 files changed