COMP: Reduce memory usage for TestCheckerboard
COMP: Reduce memory usage for TestCheckerboard

This reduces the memory usage for TestCheckerboard.tcl by reducing the
Z extents of the images from 99 to 10. This reduces the memory usage
of the test from ~170MB to ~37MB.

Change-Id: I074012d39f017f03463c240e96635820c8abdbae

hendradarwin/VTK,candy7393/VTK,mspark93/VTK,candy7393/VTK,keithroe/vtkoptix,mspark93/VTK,msmolens/VTK,mspark93/VTK,jmerkow/VTK,biddisco/VTK,keithroe/vtkoptix,collects/VTK,msmolens/VTK,SimVascular/VTK,gram526/VTK,johnkit/vtk-dev,sankhesh/VTK,mspark93/VTK,demarle/VTK,jmerkow/VTK,mspark93/VTK,sumedhasingla/VTK,collects/VTK,mspark93/VTK,keithroe/vtkoptix,sankhesh/VTK,candy7393/VTK,biddisco/VTK,collects/VTK,collects/VTK,msmolens/VTK,sankhesh/VTK,SimVascular/VTK,biddisco/VTK,candy7393/VTK,sankhesh/VTK,msmolens/VTK,jmerkow/VTK,gram526/VTK,sumedhasingla/VTK,biddisco/VTK,SimVascular/VTK,jmerkow/VTK,gram526/VTK,johnkit/vtk-dev,keithroe/vtkoptix,demarle/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,biddisco/VTK,berendkleinhaneveld/VTK,candy7393/VTK,sumedhasingla/VTK,biddisco/VTK,keithroe/vtkoptix,SimVascular/VTK,johnkit/vtk-dev,berendkleinhaneveld/VTK,hendradarwin/VTK,SimVascular/VTK,mspark93/VTK,keithroe/vtkoptix,msmolens/VTK,collects/VTK,ashray/VTK-EVM,johnkit/vtk-dev,sankhesh/VTK,sankhesh/VTK,hendradarwin/VTK,mspark93/VTK,demarle/VTK,sumedhasingla/VTK,sumedhasingla/VTK,hendradarwin/VTK,candy7393/VTK,berendkleinhaneveld/VTK,sumedhasingla/VTK,johnkit/vtk-dev,jmerkow/VTK,sankhesh/VTK,SimVascular/VTK,candy7393/VTK,berendkleinhaneveld/VTK,jmerkow/VTK,ashray/VTK-EVM,johnkit/vtk-dev,ashray/VTK-EVM,candy7393/VTK,sankhesh/VTK,demarle/VTK,gram526/VTK,keithroe/vtkoptix,collects/VTK,biddisco/VTK,gram526/VTK,demarle/VTK,keithroe/vtkoptix,jmerkow/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,demarle/VTK,sumedhasingla/VTK,hendradarwin/VTK,msmolens/VTK,ashray/VTK-EVM,ashray/VTK-EVM,gram526/VTK,gram526/VTK,demarle/VTK,msmolens/VTK,hendradarwin/VTK,ashray/VTK-EVM,ashray/VTK-EVM,johnkit/vtk-dev,ashray/VTK-EVM,demarle/VTK,msmolens/VTK,berendkleinhaneveld/VTK,sumedhasingla/VTK,SimVascular/VTK,hendradarwin/VTK,gram526/VTK