Typo in javadoc of NotificationManager#addAutomaticZenRule

     * <p>
     * Throws a SecurityException if policy access is granted to this package.
     * See {@link #isNotificationPolicyAccessGranted}.

The security exception should be thrown when policy access is NOT granted
Test: no test required. documentation change only
Fix: 138459179
Change-Id: I980392104cb38e921b6eafd1a8897b374e73b83c