fix dnssec test

[danawillow]

Moved dnssec into its own test since it can't be used with private zones and also can't be updated (actually I'm pretty sure that it can, but that should be fixed in a future PR. My impression from looking at the docs is that all fields can be updated, but that needs testing and I don't feel like doing that right now).

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[all]

[terraform]

[terraform-beta]

[ansible]

[inspec]

[modular-magician]

Hi! I'm the modular magician, I work on Magic Modules.
This PR seems not to have generated downstream PRs before, as of f247ef1.

Pull request statuses

No diff detected in terraform-google-conversion.
No diff detected in Inspec.

New Pull Requests

I built this PR into one or more new PRs on other repositories, and when those are closed, this PR will also be merged and closed.
depends: hashicorp/terraform-provider-google-beta#777
depends: hashicorp/terraform-provider-google#3735
depends: modular-magician/ansible#267

[modular-magician]

Hi! I'm the modular magician, I work on Magic Modules.
I see that this PR has already had some downstream PRs generated. Any open downstreams are already updated to your most recent commit, c40458b.

Pull request statuses

terraform-provider-google-beta already has an open PR.
No diff detected in terraform-google-conversion.
terraform-provider-google already has an open PR.
Ansible already has an open PR.
No diff detected in Inspec.

New Pull Requests

I didn't open any new pull requests because of this PR.

[danawillow]

Your comment made me look further into what that statement meant, and when which fields are returned from the API. Marked another field as computed, added a test, and changed the wording around a little- mind taking a quick second pass?