test: Fix credential leak on airgapped feature

[dheyay]

This commit uses regex instead of the echo command to extract service tokens to prevent the leak into stdout

Why is this needed?

This PR solves all of our problems because...

Test Steps

Checklist

• [ ] I have updated or added any unit tests accordingly
• [x] I have updated or added any integration tests accordingly
• [ ] Changes here need to be documented, and this was done in:

Does this PR require extra reviews?

• [ ] Yes
• [ ] No

[github-actions[bot]]

Jira: This PR is not related to a Jira item. (The PR title does not include a SC-#### reference)

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Documentation: The changes in this PR do not require documentation changes.

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