Send "pull failed" connection event when a call pull fails.

Although this isn't explicitly used in Dialer at the moment, it was
something defined and forgotten to be used.

Bug: 29906222
Change-Id: I6b722a8fb0ddd82fa1600ac81526f650b8aa5466
diff --git a/src/com/android/services/telephony/TelephonyConnection.java b/src/com/android/services/telephony/TelephonyConnection.java
index 241d54c..cefd6c0 100644
--- a/src/com/android/services/telephony/TelephonyConnection.java
+++ b/src/com/android/services/telephony/TelephonyConnection.java
@@ -384,6 +384,10 @@
             Log.i(this, "onCallPullFailed - pull failed; swapping back to call: %s",
                     externalConnection);
 
+            // Inform the InCallService of the fact that the call pull failed (it may choose to
+            // display a message informing the user of the pull failure).
+            sendConnectionEvent(Connection.EVENT_CALL_PULL_FAILED, null);
+
             // Swap the ImsPhoneConnection we used to do the pull for the ImsExternalConnection
             // which originally represented the call.
             setOriginalConnection(externalConnection);