Add Rust `bindgen` tool to `clang-tools`.

Bug: 160803703
Change-Id: Ic895ef1e010c2938ffed5d33f5fca4153f459c14
diff --git a/vndk/tools/header-checker/android/build-prebuilts.sh b/vndk/tools/header-checker/android/build-prebuilts.sh
index 8fcdb02..94fd355 100755
--- a/vndk/tools/header-checker/android/build-prebuilts.sh
+++ b/vndk/tools/header-checker/android/build-prebuilts.sh
@@ -56,6 +56,7 @@
     )
 else
     SOONG_BINARIES=(
+        "bindgen"
         "cxx_extractor"
         "header-abi-linker"
         "header-abi-dumper"