Cleanup license metadata in external/rust/crates/clang-sys. am: a705287466

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/clang-sys/+/3201694

Change-Id: I300b9bf573307c24186f4f4f73b0bf1ab8013ad1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>