broken on Android and conflicting with FRB newer versions

[patmuk]

Hi,

first, thanks for providing your code!

I noticed two problems:

1. When compiling the example for the android emulator I am getting a compiler error (101) from the rust compilations in Agent_dart_ffi.
2. The Flutter-Rust-Bridge dependency is limited to 2.5.1. As FBRs toolchain need to be aligned (meaning all code has to be generated with the same FRB version) it conflicts with my project.

Thus, I took the liberty to fork your code and remove the dependency of agent_dart and FRB :)
Note that I removed the Decryption and Encryption functions as well - as these are anyways not done in the Secure Enclave.

Thus this can be used better for more projects :) In my research I did not find a project, neither flutter nor rust, which integrates with Strongbox and Secure Enclave and exposes the getSharedSecret API.

Not that almost none of the code in utils is needed, for a minimal stripped down version these can be removed as well. But I find these convenience functions helpful and left them for the users reuse :) Thanks for these as well :).

I mainly want to inform you of my fork and why I did so.
If you want to take over my fork and integrate this less dependent version with your projects - feel free to do so!

[AlexV525]

@patmuk Hi, since agent_dart has been recently upgraded, you should no longer encounter FRB conflicts (require FRB 2.11 or later).

Regarding the decryption/encryption, they are implemented because we run related actions right after we generate shared secrets, so consider them as bonus points. But feel free to fork and make modifications; it should be easier if you are using the latest agent_dart.