Make sure that we request a ringback on SIP connections.

Bug: 17383445
Change-Id: Ie8399453a381216e22087362e37703acbd96f311
diff --git a/sip/src/com/android/services/telephony/sip/SipConnection.java b/sip/src/com/android/services/telephony/sip/SipConnection.java
index 583fa0e..08ca2f0 100644
--- a/sip/src/com/android/services/telephony/sip/SipConnection.java
+++ b/sip/src/com/android/services/telephony/sip/SipConnection.java
@@ -230,6 +230,8 @@
                 case DIALING:
                 case ALERTING:
                     setDialing();
+                    // For SIP calls, we need to ask the framework to play the ringback for us.
+                    setRequestingRingback(true);
                     break;
                 case INCOMING:
                 case WAITING: