Update any.thrift to use `v1alpha`
Update any.thrift to use `v1alpha`

Summary:
once hs2 supports package annotations, we can add them directly to the LANGUAGES constant.

Note that using this constant or 'v1beta' removes 'legacy' APIs, and we should likely do this to a lot more files.

Reviewed By: kvchen

Differential Revision: D36583993

fbshipit-source-id: 4ee2b3d24a091f6374f3c1ffb435868e4e13f4f1

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift