adding cpu_overcommit_type and updating tests

[megan07]

I think this should have been implemented as part of hashicorp/terraform-provider-google#5416

I also hard-coded the tests because the need to be type n1/n2 and this will guarantee that they are.

Fixes hashicorp/terraform-provider-google#6591

Also, I put the test for this in ComputeInstance tests because it made sense, but if you think i should have a separate test in the node template tests, I can do that too.

Release Note Template for Downstream PRs (will be copied)

compute: added `cpu_over_commit_type` to `google_compute_node_template`

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 1 file changed, 4 insertions(+), 10 deletions(-))
Terraform Beta: Diff ( 3 files changed, 38 insertions(+), 10 deletions(-))
Inspec: Diff ( 4 files changed, 10 insertions(+))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=120549"

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 1 file changed, 4 insertions(+), 10 deletions(-))
Terraform Beta: Diff ( 3 files changed, 38 insertions(+), 10 deletions(-))
Inspec: Diff ( 4 files changed, 10 insertions(+))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=120779"

[rileykarson]

Seems like a reasonable place for the test to me!