Remove 2D uniform grid from cylinder mapper test

This type of grid does not seem to be supported.
Status Job ID Name Coverage
  External
passed cdash-buildbot

passed vtk-m-dragnipur-osx-shared-debug+32bit_ids+64bit_coords+clang+tbb

00:11:32

passed vtk-m-dragnipur-osx-static-release+64bit_coords+clang+tbb

00:16:11

passed vtk-m-osheim-windows-shared-debug+ninja-vs-2017+tbb

00:23:13

passed vtk-m-osheim-windows-static-release+ninja-vs-2017+tbb

00:29:07