qadevOOo: use System.arraycopy

Change-Id: Ibbac337b481e138ff9bfaa9d350b52e368ba5f2b
Reviewed-on: https://gerrit.libreoffice.org/11355
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>