Fixes to make crate safe to migrate.

* Don't compile the C code in build.rs, because it pollutes the out
  directory and we have a custom build rule to do it. Add a
  corresponding patch.
* Add Android.bp.patch to include the custom build rule.
* Move src/out to out

Bug: http://b/339424309
Test: treehugger
Change-Id: I3dbc267dc1bf169e4dcde71e1cc52c30ef752088
6 files changed