vulkan: fix back compat with Android Oreo and below

buffer_handle_t definition was previously inside the deprecated
system/core/include/system/window.h.

Signed-off-by: Yiwei Zhang <zzyiwei@chromium.org>
Acked-by: Chia-I Wu <olvaffe@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11301>

include/vulkan/vk_android_native_buffer.h

@@ -20,6 +20,12 @@
 #ifdef ANDROID
 #include <cutils/native_handle.h>
 #include <vulkan/vulkan.h>
+
+#if ANDROID_API_LEVEL < 28
+/* buffer_handle_t was defined in the deprecated system/window.h */
+typedef const native_handle_t *buffer_handle_t;
+#endif
+
 #else
 typedef void *buffer_handle_t;
 #endif