Fix NPE in VCardService

Bug: 7967011
Change-Id: Idf53807959a40f164ef0c163479a75988de71e44
diff --git a/src/com/android/contacts/common/vcard/VCardService.java b/src/com/android/contacts/common/vcard/VCardService.java
index 07c2a3c..e2adbbd 100644
--- a/src/com/android/contacts/common/vcard/VCardService.java
+++ b/src/com/android/contacts/common/vcard/VCardService.java
@@ -175,8 +175,12 @@
 
     @Override
     public int onStartCommand(Intent intent, int flags, int id) {
-        mCallingActivity = intent.getExtras().getString(
-                VCardCommonArguments.ARG_CALLING_ACTIVITY);
+        if (intent != null && intent.getExtras() != null) {
+            mCallingActivity = intent.getExtras().getString(
+                    VCardCommonArguments.ARG_CALLING_ACTIVITY);
+        } else {
+            mCallingActivity = null;
+        }
         return START_STICKY;
     }