fix GCP credentials key extraction

[orouz]

Summary of your changes

@Omolola-Akinleye noticed the deployment script fails, and after taking a look in turns out the response we now get in gcloud shell is different so the key extraction (which is what failed) needs to be a little different.

Screenshot/Data

this is how it looks in gcloud shell after running the script:

• fixes [GCP] Automated credentials creation flow for agentless #2005

[mergify]

This pull request does not have a backport label. Could you fix it @orouz? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[github-actions]

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🟩 Passed	359
⬜ Skipped	33