fix update strategy default handling

[Zakharden]

Fixes false positive for omitted rolling update strategy. Validation: go test ./pkg/templates/updateconfig, git diff --check.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 30.88%. Comparing base (dbd7529) to head (6dd3f0f).
⚠️ Report is 310 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1179       +/-   ##
===========================================
- Coverage   62.36%   30.88%   -31.48%     
===========================================
  Files         197      239       +42     
  Lines        4854     6550     +1696     
===========================================
- Hits         3027     2023     -1004     
- Misses       1439     4351     +2912     
+ Partials      388      176      -212     

Flag	Coverage Δ
unit	30.88% <100.00%> (-31.48%)	⬇️

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[Zakharden]

I see this as code-complete on the branch and currently blocked only by maintainer flow. Please re-run checks/review and let me know if anything else is required.

[Zakharden]

I confirmed this branch is code-complete and tests pass; patch coverage is green but codecov/project remains failing due repository-wide project coverage baseline behavior.

Please rerun maintainer-side checks/coverage step when convenient; no further local code changes are pending.

[Zakharden]

FYI branch is code-complete; and tests are green, while only remains failing. Please re-run maintainer-side coverage/review flow so we can finalize.

[Zakharden]

Branch is code-complete and tests pass. codecov/patch is green; only codecov/project remains failing, likely due baseline/project-coverage behavior. Please re-run maintainer-side coverage/review and advise if further adjustments are needed.