this UNO interface is not being used an a real UNO API, so replace it
with something that doesn't pass around 3 doubles in a Sequence
Change-Id: I39d8ae03a3e861daba87f46686c0f93815bb1805
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128292
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>