Make test fields private in Go unit tests

[tariq-hasan]

What this PR does / why we need it:

Following the suggestion to keep the test fields private within Go unit tests, this PR implements the necessary changes.

The unit tests for Go have been run and validated in this CI Workflow.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Checklist:

• Docs included if any changes are user facing

[tariq-hasan]

I wonder if we should re-run Unit Test 1.27.1 given that this issue was flagged before in other PRs and jobs were restarted.

Other jobs look to be okay.

I was also wondering if a dedicated issue needs to be opened to look into this.

[tenzen-y]

I wonder if we should re-run Unit Test 1.27.1 given that this issue was flagged before in other PRs and jobs were restarted.

Other jobs look to be okay.

I was also wondering if a dedicated issue needs to be opened to look into this.

@tariq-hasan I tried to re-run 5 times, but that case never succeeded in CI...
In your local, what happened?

[tenzen-y]

I wonder if we should re-run Unit Test 1.27.1 given that this issue was flagged before in other PRs and jobs were restarted.
Other jobs look to be okay.
I was also wondering if a dedicated issue needs to be opened to look into this.

@tariq-hasan I tried to re-run 5 times, but that case never succeeded in CI... In your local, what happened?

After I restarted it 6 times, that case succeeded. That case is so flaky...

[tenzen-y]

I was also wondering if a dedicated issue needs to be opened to look into this.

Actually, we already have a dedicated issue: #2269

[tenzen-y]

Thank you!
/lgtm
/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tariq-hasan, tenzen-y

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