vulkan: Declare VK_ANDROID_external_memory_android_hardware_buffer

Test: build
Change-Id: I02d4790f7a4d5ccb0c6e5b43fab92e89ce8322db
diff --git a/vulkan/api/platform.api b/vulkan/api/platform.api
index eb0124d..41f398d 100644
--- a/vulkan/api/platform.api
+++ b/vulkan/api/platform.api
@@ -43,6 +43,7 @@
 
 // VK_USE_PLATFORM_ANDROID_KHR
 @internal class ANativeWindow {}
+@internal class AHardwareBuffer {}
 @internal type void* buffer_handle_t
 
 // VK_USE_PLATFORM_WIN32_KHR