layers: Add missing NVSCI checking for VkMemoryAllocateInfo

According to the doc, If the parameters define an import operation
and the external handle type is
VK_EXTERNAL_MEMORY_HANDLE_TYPE_SCI_BUF_BIT_NV, allocationSize
is ignored.

Currently VVL will report check failure on this, add the checking
for VkImportMemorySciBufInfoNV to fix this problem.