Android CI is broken

[Amanieu]

This seems to be related to rust-lang/rust#103673. Essentially we need to update the CI scripts to use a newer NDK version. Possible inspiration can be taken from the rust-libc CI scripts, which are similar to the ones in this crate.

[workingjubilee]

cc aarch64 android maintainers: @chriswailes @maurer @mgeisler

Hello! Our backtrace crate is deep in arrears on maintenance and we could use all the help we can get, specifically with some Android issues. It should be a relatively simple fix, tho'.

[chriswailes]

I'd be happy to take a look at this tomorrow.

[chriswailes]

Sorry for the delay. It looks like #534 will bring the CI definition up to date.

[workingjubilee]

Completely fine! It's great to have this taken care of!