layers: Fix typo in layer validation details doc
layers: Fix typo in layer validation details doc

DynamicBlendConstantsNotBound was misspelled.

Change-Id: I33f4d53e336dc39b5f23583ee24df88441a339ac

elongbug/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers