Summary:
OpenBCM libraries are stored with git LFS. As a result, fetcher fetches LFS pointers and not the contents. Use git-lfs to pull the real contents before copying to install dir using NoopBuilder.
In future, if more builders require git-lfs, we would consider installing
git-lfs as part of the sandcastle infra as against repeating similar
 logic for each builder that requires git-lfs.

Reviewed By: wez

Differential Revision: D18759806

fbshipit-source-id: f988a0460107bc0685e7aba107daba9ed88f71e7