[experiments] Cannot execute experiment with shared toolchain

The platform tells me the toolchain isn't public, but the toolchain is accessible to me.

2 issues:

1. It should not say "it isn't public", but "it isn't accessible"
2. The said toolchain is accessible to me (and to you as well).

Check here by forking this ready to use experiment:

http://beatweb-staging/experiments/setup/chichan/chichan/full_mlbphs_projection/1/MLBPHLDA1/