Some platforms don't support hostfxr but we can use the coreclr/monosgen library directly to initialize the runtime.
Android exports now use the `android` runtime identifier instead of `linux-bionic`, this removes the restrictions we previously had:
- Adds support for all Android architectures (arm32, arm64, x32, and x64), previously only the 64-bit architectures were supported.
- Loads `System.Security.Cryptography.Native.Android` (the .NET library that binds to the Android OS crypto functions).
We want to replace libnethost as it gives us issues with some compilers.
Our implementation tries to mimic libnethost's hostfxr_resolver search
logic. We try to use the same function names for easier comparing in
case we need to update this in the future.
