Adding resiliency to the repo clone command

[EricLeFort]

Description

Makes the repo cloning step more resilient in case the repo already exists.

Tests

I ran a keras test that was failing due to this issue and it is now passing that step.

List links for your tests (use go/shortn-gen for any internal link):
http://shortn/_RBZjspOxFM

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run one-shot tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed.