STYLE: Clean up CD tests of unnecessary gtest init

...tection/Testing/imstkBidirectionalPlaneToSphereCDTest.cpp

...sionDetection/Testing/imstkMeshToMeshBruteForceCDTest.cpp

...ionDetection/Testing/imstkPointSetToOrientedBoxCDTest.cpp

...CollisionDetection/Testing/imstkPointSetToPlaneCDTest.cpp

...ollisionDetection/Testing/imstkSphereToCylinderCDTest.cpp

.../CollisionDetection/Testing/imstkSphereToSphereCDTest.cpp

...CollisionDetection/Testing/imstkTetraToLineMeshCDTest.cpp

...CollisionDetection/Testing/imstkTetraToPointSetCDTest.cpp

...ection/Testing/imstkUnidirectionalPlaneToSphereCDTest.cpp