Add SyncState class for calendar provider.

        // TODO: fill out this class when we actually start utilizing extendedproperties

        // in the calendar application.

   }

    /**

     * A table provided for sync adapters to use for storing private sync state data.

     *

     * @see SyncStateContract

     */

    public static final class SyncState implements SyncStateContract.Columns {

        /**

         * This utility class cannot be instantiated

         */

        private SyncState() {}

        public static final String CONTENT_DIRECTORY =

                SyncStateContract.Constants.CONTENT_DIRECTORY;

        /**

         * The content:// style URI for this table

         */

        public static final Uri CONTENT_URI =

                Uri.withAppendedPath(Calendar.CONTENT_URI, CONTENT_DIRECTORY);

    }

}