Android support

[chertov]

I am trying to generate android bindings chertov@4be4f7f
the solution is simple, but i don't know how it will work with different ORT_STRATEGY
i would like to use NNAPI acceleration

[nbigaouette]

I am not in a position where I can test this, but looking at your commit I did not see anything that would prevent a merge. I guess there we can simply fail the build if ORT_STRATEGY is set to something else than system.

I'd suggest to open a PR to include your changes.