Conference call merge button visibility issue. (1/2)

- Calling onConferenceableCallsChanged listener on change of Call.
- This was preventing the change in conferenceable calls from being
communicated to the InCall UI.

Bug: 17767618
Change-Id: Ib9f7c9dbc0d05089475b6fe79e338be2c32e8698
diff --git a/src/com/android/server/telecom/Call.java b/src/com/android/server/telecom/Call.java
index 9588d47..44e49a4 100644
--- a/src/com/android/server/telecom/Call.java
+++ b/src/com/android/server/telecom/Call.java
@@ -905,6 +905,10 @@
     void setConferenceableCalls(List<Call> conferenceableCalls) {
         mConferenceableCalls.clear();
         mConferenceableCalls.addAll(conferenceableCalls);
+
+        for (Listener l : mListeners) {
+            l.onConferenceableCallsChanged(this);
+        }
     }
 
     List<Call> getConferenceableCalls() {