Have project-clone container clone git submodules

[dkwon17]

Description

WORKAROUND: run git submodule update --init in a tooling container to clone submodules.

The project clone container does not clone submodules for git repositories with submodules. If cloning a git repo with a submodule, it would be great if the submodule is also cloned.

Additional context

Can try to reproduce the issue with this repo: https://github.com/dkwon17/submodule-test