Ensure call log pending intent on missed call notification is immutable.

Test: Modify telecom to always display notification; verify you can still
get to the call log from the missed call notification hosted by Telecom.
Fixes: 155650969

Change-Id: I07fdc66b441cdbb7fdf3fad8842fe17a2126e445
diff --git a/src/com/android/server/telecom/ui/MissedCallNotifierImpl.java b/src/com/android/server/telecom/ui/MissedCallNotifierImpl.java
index e64e67c..a0eca8f 100644
--- a/src/com/android/server/telecom/ui/MissedCallNotifierImpl.java
+++ b/src/com/android/server/telecom/ui/MissedCallNotifierImpl.java
@@ -472,7 +472,7 @@
         TaskStackBuilder taskStackBuilder = TaskStackBuilder.create(mContext);
         taskStackBuilder.addNextIntent(intent);
 
-        return taskStackBuilder.getPendingIntent(0, 0, null, userHandle);
+        return taskStackBuilder.getPendingIntent(0, PendingIntent.FLAG_IMMUTABLE, null, userHandle);
     }
 
     /**