add Android.bp to libthreadpool am: 0683ec4325 am: 5629b4b805 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/threadpool/+/2566131 Change-Id: If30287caa291c708e86ca5812c6e03954ee98613 Signed-off-by: Automerger Merge Worker <[email protected]>