Depend on vulkan headers in angle_gpu_info_util

angle_gpu_info_util is capable of dynamically loading vulkan without
a dependency but it still requires the dependency on the headers to
compile on some systems.

BUG= b:153394225

Change-Id: I698a825499364c09faea39384d25d454f83955b3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2139414
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

BUILD.gn

@@ -331,6 +331,7 @@ angle_static_library("angle_gpu_info_util") {
 
   if (is_android || is_fuchsia) {
     sources += libangle_gpu_info_util_vulkan_sources
+    deps += [ "$angle_root/third_party/vulkan-headers/src:vulkan_headers" ]
   }
 
   if (is_android) {