Hide null account in customize screen

Test: manually verified that there was no device account shown
on the customize screen.

BUG=62689233

Change-Id: I1786f6505d29878b80930581ca0883121900da74
diff --git a/src/com/android/contacts/list/CustomContactListFilterActivity.java b/src/com/android/contacts/list/CustomContactListFilterActivity.java
index 9b0c896..425ee7e 100644
--- a/src/com/android/contacts/list/CustomContactListFilterActivity.java
+++ b/src/com/android/contacts/list/CustomContactListFilterActivity.java
@@ -163,6 +163,12 @@
             // ContactsContract.Settings
             for (AccountInfo info : sourceAccounts) {
                 final AccountWithDataSet account = info.getAccount();
+                // Don't include the null account because it doesn't support writing to
+                // ContactsContract.Settings
+                if (account.isNullAccount()) {
+                    continue;
+                }
+
                 final AccountDisplay accountDisplay = new AccountDisplay(resolver, info);
 
                 final Uri.Builder groupsUri = Groups.CONTENT_URI.buildUpon()