add gkehub feature tests

[kotarsky]

adding new tests for gkehub.googleapis.com/Feature

gkehub: added tests field to `gkehub.googleapis.com/Feature` resource

[github-actions[bot]]

Hello! I am a robot. Tests will require approval from a repository maintainer to run.

@ScottSuarez, a repository maintainer, has been assigned to review your changes. If you have not received review feedback within 2 business days, please leave a comment on this PR asking them to take a look.

You can help make sure that review is quick by doing a self-review and by running impacted tests locally.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

terraform-google-conversion: Diff ( 4 files changed, 41 insertions(+))

[kotarsky]

@rileykarson Can you review it again?