Null protect getUi() in configureAnswerTargetsForSms

Bug: 22442874
Change-Id: Id3d522415db3a551c646950a7023478226182ae9
diff --git a/src/com/android/incallui/AnswerPresenter.java b/src/com/android/incallui/AnswerPresenter.java
index 1453fa5..a5a88ff 100644
--- a/src/com/android/incallui/AnswerPresenter.java
+++ b/src/com/android/incallui/AnswerPresenter.java
@@ -265,6 +265,9 @@
     }
 
     private void configureAnswerTargetsForSms(Call call, List<String> textMsgs) {
+        if (getUi() == null) {
+            return;
+        }
         mHasTextMessages = textMsgs != null;
         boolean withSms =
                 call.can(android.telecom.Call.Details.CAPABILITY_RESPOND_VIA_TEXT)