Add Missing Unit Tests for recommender/model/types.go in VPA

[omerap12]

Which component are you using?:
VPA

Is your feature request designed to solve a problem? If so describe the problem this feature should solve.:

The VPA recommender file located at vertical-pod-autoscaler/pkg/recommender/model/types.go currently lacks complete unit test coverage. I added some tests in PR #7428, but a few functions are still missing test cases.

Describe the solution you'd like.:
Once PR #7428 is merged, add additional unit tests to ensure complete coverage of the recommender/model/types.go file.

Describe any alternative solutions you've considered.:
None.

Additional context.:
None.

[omerap12]

/assign
cc @adrianmoisey

[omerap12]

/area vertical-pod-autoscaler