ptr_meta_derive: Generate Android.bp file

Use the cargo_embargo tool to generate the cargo_embargo.json file.
Use the cargo_embargo tool to generate the Android.bp file.

cargo_embargo autoconfig cargo_embargo.json
cargo_embargo generate cargo_embargo.json

Test: m libptr_meta_derive
Change-Id: Iba1f7ca3ce6a0693178acd9ff2480b8f4288cf78