Use SmsManager for reject call with SMS

Instead of starting a service to send SMS when a call is
rejected, we now use the SmsManager#sendTextMessage API.

Bug: 62048610
Test: Reject call and send SMS
Change-Id: I8d648ab5c3e35539d1387ece4d11acc1c30c8ea2
Merged-In: I8d648ab5c3e35539d1387ece4d11acc1c30c8ea2