Add IN_DEFAULT_DIRECTORY to contract

I want to expose this flag so that gmail can sort
based on it. Plus, it provides generally useful information.

Bug: 13173524
Change-Id: I93a35f8822b55f97b15e1fbb783110e3674c1622

core/java/android/provider/ContactsContract.java

@@ -900,6 +900,14 @@ public final class ContactsContract {
          */
         public static final String PHOTO_THUMBNAIL_URI = "photo_thumb_uri";
 
+        /**
+         * Flag that reflects whether the contact exists inside the default directory.
+         * Ie, whether the contact is designed to only be visible outside search.
+         *
+         * @hide
+         */
+        public static final String IN_DEFAULT_DIRECTORY = "in_default_directory";
+
         /**
          * Flag that reflects the {@link Groups#GROUP_VISIBLE} state of any
          * {@link CommonDataKinds.GroupMembership} for this contact.