Network Connectivity Hub

[c2thorn]

Part of hashicorp/terraform-provider-google#10514

If this PR is for Terraform, I acknowledge that I have:

• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
• Read the Release Notes Guide before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

`google_network_connectivity_hub`

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 10 files changed, 757 insertions(+), 18 deletions(-))
Terraform Beta: Diff ( 10 files changed, 761 insertions(+), 22 deletions(-))
TF Validator: Diff ( 1 file changed, 1 insertion(+))

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccApigeeEnvironmentIamBindingGenerated|TestAccApigeeEnvironmentIamMemberGenerated|TestAccApigeeEnvironmentIamPolicyGenerated|TestAccCloudFunctionsFunction_vpcConnector|TestAccContainerNodePool_withInvalidUpgradeSettings|TestAccServiceNetworkingPeeredDNSDomain_basic|TestAccNetworkConnectivityHub_BasicHub You can view the result here: https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=235008

[modular-magician]

Tests failed during RECORDING mode: TestAccCloudFunctionsFunction_vpcConnector|TestAccContainerNodePool_withInvalidUpgradeSettings Please fix these to complete your PR

[slevenick]

Overall looks good to me, but a couple questions.

Is this resource worth releasing without the partner resource?

Do we need the DCL upgrade to add this? I believe there is a breaking change in an osconfig resource here: https://github.com/modular-magician/terraform-provider-google-beta/compare/auto-pr-5574-old..auto-pr-5574#diff-10ce2c336edf0b7efb1851d634d178e963bcffcc179223e09c1d6e224f112ec7R706

[slevenick]

Huh, looks like a docs bug where we don't print both the validate & enforce block structures, so unrelated to this

[c2thorn]

@slevenick

Is this resource worth releasing without the partner resource?

Not really, but at least the next review can be smaller in scope. Appreciate the time!

Do we need the DCL upgrade to add this? I believe there is a breaking change in an osconfig resource here:

I missed that, and not sure why that appears in this PR. But I'll look into fixing the bug.

[c2thorn]

partner resource is ready, so I'm merging this