Use UserManager.isSystemUser API

    }

    /**

     * Whether a user handle associated with the current user is that of the primary owner. That is,

     * whether there is a user handle which has an id which matches the owner's handle.

     * @return Whether the current user is the primary user.

     */

    private boolean isPrimaryUser() {

        UserManager userManager = (UserManager) getSystemService(Context.USER_SERVICE);

        List<UserHandle> userHandles = userManager.getUserProfiles();

        for (int i = 0; i < userHandles.size(); i++){

            if (userHandles.get(i).myUserId() == OWNER_HANDLE_ID) {

                return true;

            }

        }

        return false;

        final UserManager userManager = (UserManager) getSystemService(Context.USER_SERVICE);

        return userManager.isSystemUser();

    }

}