In commit a9ec212c the internal
default name of the layer, which holds form controls, was changed to
controls, the same name as used in file format and UNO. Users of
the class SdrLayerAdmin have to set the control layer name
explicitly in case they want an own, different name.

Change-Id: Ia08a85a4d01a75ee2c5115da25b2a409204ccc01
Reviewed-on: https://gerrit.libreoffice.org/61447
Tested-by: Jenkins
Reviewed-by: Regina Henschel <rb.henschel@t-online.de>