vulkan: update Vulkan headers to 1.1.68

Key changes from 1.1.61:
* Introduced split headers:
  * vulkan_core.h provides all declarations that don't depend on
    platform-specific headers
  * vulkan_android.h provides Android-specific declarations
  * vulkan.h is retained for source compatibility, and includes both
    of the above; vulkan_android.h is conditional on
    VK_USE_PLATFORM_ANDROID_KHR
* Re-defined symbols for extensions that were merged into Vk1.1 as
  typedefs/aliases for the new core symbols.
* New extensions:
  * VK_EXT_conservative_rasterization
  * VK_EXT_debug_utils
  * VK_EXT_external_memory_dma_buf
  * VK_EXT_external_memory_host
  * VK_EXT_global_priority
  * VK_EXT_queue_family_foreign
  * VK_AMD_shader_image_load_store_lod
  * VK_AMD_shader_info

Test: build
Change-Id: I84cdb4c24eed27ead99047951f795ccafa0bfc9a
diff --git a/vulkan/Android.bp b/vulkan/Android.bp
index 6107088..35c6e59 100644
--- a/vulkan/Android.bp
+++ b/vulkan/Android.bp
@@ -19,6 +19,8 @@
     srcs: [
         "include/vulkan/vk_platform.h",
         "include/vulkan/vulkan.h",
+        "include/vulkan/vulkan_core.h",
+        "include/vulkan/vulkan_android.h",
     ],
     license: "include/vulkan/NOTICE",
 }