Use upstream Vulkan headers from external/vulkan-headers

vk_android_native_buffer.h and vk_layer_interface.h remain, since
they're Android-internal additions and not provided by the upstream
API header repository.

Bug: 129696724
Test: make checkbuild
Change-Id: If4677d08a6891b18ce347e3fa3be393fc6111fc8
Merged-In: If4677d08a6891b18ce347e3fa3be393fc6111fc8
diff --git a/vulkan/libvulkan/Android.bp b/vulkan/libvulkan/Android.bp
index e1a1ebc..993b751 100644
--- a/vulkan/libvulkan/Android.bp
+++ b/vulkan/libvulkan/Android.bp
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Headers module is in frameworks/native/vulkan/Android.bp.
+// Headers module is in external/vulkan-headers/Android.bp.
 ndk_library {
     name: "libvulkan",
     symbol_file: "libvulkan.map.txt",