[usecase-tizen] Imporve SystemSetting IncomingCall tizen usecase

- Change to 3 button: set, get path, play.

Impacted TCs num(designed): New 0, Update 1, Delete 0
Unit test Platform: Tizen M0
Tizen test result summary: Pass 1, Fail 0, Blocked 0
Merge pull request #686 from xinliux/xinliux/usecase/systemincoming

[usecase-tizen] Imporve SystemSetting IncomingCall tizen usecase