The view uses the SdrLayerIDSet bitfield in layer ID order.
But file format knows no layer IDs and on loading the
bitfield is interpreted in the layer order given by
<draw:layer-set> element. Therefore reorder the bits on
saving according <draw:layer-set>, which is order in
SdrLayerAdmin.

Change-Id: Id349dc7f42338e35ca8cc3b6409d061213b01691
Reviewed-on: https://gerrit.libreoffice.org/60178
Tested-by: Jenkins
Reviewed-by: Regina Henschel <rb.henschel@t-online.de>