layers: Fix paramter_validation array name codegen
layers: Fix paramter_validation array name codegen

Replace std::string with ParameterName for the generated
parameter_validation layer code so that the parameter names
printed by the generated code contain the correct array
subscript values.  Also updates the parameter_validation
tests to reflect the change to the printed names.

Issues-Addressed: GitHub #462
Change-Id: I3032e08052fc003ba066bbe613e5faf3ed049964

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools