test: not nil defense broke logic

[jackfrancis]

Reason for Change:

This PR fixes a logical bug introduced in #3857. Many of our test configs don't declare a kubernetesConfig object in the input API model, which means environment variable-derivd service principal injection will be skipped. That's not what we want!

Issue Fixed:

Credit Where Due:

Does this change contain code from or inspired by another project?

• No
• Yes

If "Yes," did you notify that project's maintainers and provide attribution?

• No
• Yes

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

[acs-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jackfrancis

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [jackfrancis]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov]

Codecov Report

Merging #3881 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3881   +/-   ##
=======================================
  Coverage   72.83%   72.83%           
=======================================
  Files         149      149           
  Lines       23203    23203           
=======================================
  Hits        16900    16900           
  Misses       5182     5182           
  Partials     1121     1121           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1dd327a...30fa6d7. Read the comment docs.