Declare the headers of the ndk_library

This creates a dependency edge between the ndk_library and its headers,
which should be a no-op in regular Soong builds. This dependency edge
will be used in the Multi-tree project to export the relevant .h files into a well
known location

Formatting changes are from bpfmt

Test: m nothing
Bug: 239044713
Change-Id: Id037828b4b7f71ffe0d6a7841253c610eef3af31
diff --git a/vulkan/libvulkan/Android.bp b/vulkan/libvulkan/Android.bp
index 5719b5c..a87f82f 100644
--- a/vulkan/libvulkan/Android.bp
+++ b/vulkan/libvulkan/Android.bp
@@ -27,6 +27,9 @@
     symbol_file: "libvulkan.map.txt",
     first_version: "24",
     unversioned_until: "current",
+    export_header_libs: [
+        "ndk_vulkan_headers",
+    ],
 }
 
 cc_library_shared {