Fix NullPointerException in InCallUI with CallTimer.

bug: 10325158
Change-Id: Ie7e89c2e1e3038df89387e99de6849ed12203824
diff --git a/InCallUI/src/com/android/incallui/CallCardPresenter.java b/InCallUI/src/com/android/incallui/CallCardPresenter.java
index 330957e..60486f4 100644
--- a/InCallUI/src/com/android/incallui/CallCardPresenter.java
+++ b/InCallUI/src/com/android/incallui/CallCardPresenter.java
@@ -150,13 +150,15 @@
         final CallCardUi ui = getUi();
 
         if (ui == null || mPrimary == null || mPrimary.getState() != Call.State.ACTIVE) {
-            ui.setPrimaryCallElapsedTime(false, null);
+            if (ui != null) {
+                ui.setPrimaryCallElapsedTime(false, null);
+            }
             mCallTimer.cancel();
+        } else {
+            final long callStart = mPrimary.getConnectTime();
+            final long duration = System.currentTimeMillis() - callStart;
+            ui.setPrimaryCallElapsedTime(true, DateUtils.formatElapsedTime(duration / 1000));
         }
-
-        final long callStart = mPrimary.getConnectTime();
-        final long duration = System.currentTimeMillis() - callStart;
-        ui.setPrimaryCallElapsedTime(true, DateUtils.formatElapsedTime(duration / 1000));
     }