A fork of cargo2android, initially aimed at big imports like crosvm. * Faster run time when there are many packages (30 min -> 1 min for crosvm). * `--reuse-cargo-out` feature allows iterating on most of the config with sub second run time. * Most options can be specified per-package. Bug: 261486161 Test: ran on crosvm and checked diffs Change-Id: Iaf3f4732e828a6f8b281f0e63fe1e0e1e9e98631