Add an AArch64 Android test

[workingjubilee]

Rust supports aarch64-linux-android and that is the most commonly used Android target, I expect, so we should test building for that as well.

[NobodyXu]

Do we need cross-rs to run test?

I'm not very familiar with Android, ecosystem, I suspect we would also need to install some system-level dependencies for it to work.