vulkan: update Vulkan headers to 1.0.38

Test: make ; mmm frameworks/native/vulkan
Change-Id: I6437dc951bd694cb848f75d0de7eb7dbe8a4d1fe
diff --git a/vulkan/libvulkan/api_gen.cpp b/vulkan/libvulkan/api_gen.cpp
index f022899..af70fa1 100644
--- a/vulkan/libvulkan/api_gen.cpp
+++ b/vulkan/libvulkan/api_gen.cpp
@@ -453,8 +453,10 @@
         "vkEnumerateInstanceLayerProperties",
         "vkEnumeratePhysicalDevices",
         "vkGetInstanceProcAddr",
+        "vkGetPhysicalDeviceExternalImageFormatPropertiesNV",
         "vkGetPhysicalDeviceFeatures",
         "vkGetPhysicalDeviceFormatProperties",
+        "vkGetPhysicalDeviceGeneratedCommandsPropertiesNVX",
         "vkGetPhysicalDeviceImageFormatProperties",
         "vkGetPhysicalDeviceMemoryProperties",
         "vkGetPhysicalDeviceProperties",