[WIP] sandvich-android

[carolkng]

Sandvich-ios but on android

Currently uses Thom's RustObject + RustResult to avoid memory leaks
let's not do this now ^^ in the interest of time

[thomcc]

Currently uses Thom's RustObject + RustResult to avoid memory leaks

Sadly, without the changes to the FFI I had made at the same time to return Results by value, this still leaks memory whenever results are returned.

(The approach I think we've settled on in the mentat pr gets rid of the ExternResult/RustResult type anyway since it's error prone, and instead FFI functions an out parameter. This gives you additional type safety in the Java code, at the cost of being a little more tedious to write. The swift code can be adapted to have more type safety (like the java) but there are a few drawbacks, but it's no worse off in this approach, and much less likely to leak memory.)

[mhammond]

I suspect we don't want this .so checked in - I know that mentat etc uses a git symlink which might make more sense. (Obviously this isn't important for the WIP, but probably makes sense to address before merging)

[carolkng]

Closing because most of the work has been ported over to the android-components repo (library, sample app) and I'm not sure it makes sense to maintain the sample app in both repos any more.