Build for armv7-linux-androideabi

Currently armv7 builds are not working within the nix flake from p2p-shipyard due to this upstream issue with building `corosensei`: https://github.com/Amanieu/corosensei/issues/39

I am able to build `corosensei` directly for armv7-linux-androideabi with the following `.cargo/config.toml`:
```
[target.armv7-linux-androideabi]
linker = "/opt/android-studio/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi35-clang"
rustflags = ["-C", "link-arg=-Wl,-z,notext"]
```

I'm expecting we will need to resolve this issue ourselves, and it is likely related to the p2p-shipyard nix flake setup.