am 1180f2a0: Merge "Remove ringtone API from SipAudioCall." into gingerbread

Merge commit '1180f2a099a134c40f923c7e4162a5e7d7ca0184' into gingerbread-plus-aosp

* commit '1180f2a099a134c40f923c7e4162a5e7d7ca0184':
  Remove ringtone API from SipAudioCall.