Handle null in vCard import

PendingIntent#getActivity() doesn't accept null while
the method allows null.

Bug: 3360839
Change-Id: Ibebaab64b6091679c553f942a48215a8d5b05d3d
diff --git a/src/com/android/contacts/vcard/VCardService.java b/src/com/android/contacts/vcard/VCardService.java
index 13d938c..6422163 100644
--- a/src/com/android/contacts/vcard/VCardService.java
+++ b/src/com/android/contacts/vcard/VCardService.java
@@ -486,7 +486,8 @@
                 .setSmallIcon(android.R.drawable.stat_sys_download_done)
                 .setContentTitle(title)
                 .setContentText(description)
-                .setContentIntent(PendingIntent.getActivity(context, 0, intent, 0))
+                .setContentIntent(PendingIntent.getActivity(context, 0,
+                        (intent != null ? intent : new Intent()), 0))
                 .getNotification();
     }