Fill in missing bits of LAYER variable for printing/plotting.

Fixes https://gitlab.com/kicad/code/kicad/issues/11788

(cherry picked from commit f22cf1cc3a)

common/plotters/common_plot_functions.cpp

@@ -84,6 +84,7 @@ void PlotDrawingSheet( PLOTTER* plotter, const PROJECT* aProject, const TITLE_BL
     drawList.SetSheetCount( aSheetCount );
     drawList.SetFileName( fn.GetFullName() );   // Print only the short filename
     drawList.SetSheetName( aSheetDesc );
+    drawList.SetSheetLayer( plotter->RenderSettings()->GetLayerName() );
     drawList.SetProject( aProject );
     drawList.SetIsFirstPage( aIsFirstPage );