Show child number in incoming call notification.

Where a child number is present in the call extras, show it using the
text "via 650-555-1212" in the second line of the incoming call
notification.

Bug: 24585039
Change-Id: Ic9827f8518778bf5e9c36235e2e1b6525aba4928
diff --git a/src/com/android/incallui/StatusBarNotifier.java b/src/com/android/incallui/StatusBarNotifier.java
index 4d4e349..89794cd 100644
--- a/src/com/android/incallui/StatusBarNotifier.java
+++ b/src/com/android/incallui/StatusBarNotifier.java
@@ -430,10 +430,14 @@
         boolean isIncomingOrWaiting = call.getState() == Call.State.INCOMING ||
                 call.getState() == Call.State.CALL_WAITING;
 
-        if (isIncomingOrWaiting && !TextUtils.isEmpty(call.getCallSubject()) &&
-                call.getNumberPresentation() == TelecomManager.PRESENTATION_ALLOWED &&
-                call.isCallSubjectSupported()) {
-            return call.getCallSubject();
+        if (isIncomingOrWaiting &&
+                call.getNumberPresentation() == TelecomManager.PRESENTATION_ALLOWED) {
+
+            if (!TextUtils.isEmpty(call.getChildNumber())) {
+                return mContext.getString(R.string.child_number, call.getChildNumber());
+            } else if (!TextUtils.isEmpty(call.getCallSubject()) && call.isCallSubjectSupported()) {
+                return call.getCallSubject();
+            }
         }
 
         int resId = R.string.notification_ongoing_call;