Add null check when loading telephony subscriptions

SubscriptionManager.getActiveSubscriptionInfoLis() can return null and this
wasn't being handled. The linked bug was already fixed by a different change
but the additional check is good to do.

Test:
manual verify that ImportDialogFragment works with and without a SIM card

Bug 32556709

Change-Id: I325cb30b5559626d91f0f79aaa1c99b98a39b070
diff --git a/src/com/android/contacts/common/database/SimContactDao.java b/src/com/android/contacts/common/database/SimContactDao.java
index 37ad9e3..cab2906 100644
--- a/src/com/android/contacts/common/database/SimContactDao.java
+++ b/src/com/android/contacts/common/database/SimContactDao.java
@@ -207,6 +207,9 @@
                 mContext.getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE);
         final List<SubscriptionInfo> subscriptions = subscriptionManager
                 .getActiveSubscriptionInfoList();
+        if (subscriptions == null) {
+            return Collections.emptyList();
+        }
         final ArrayList<SimCard> result = new ArrayList<>();
         for (SubscriptionInfo subscriptionInfo : subscriptions) {
             result.add(SimCard.create(subscriptionInfo));