container_node_pool : add gvnic support

[ScottSuarez]

Release Note Template for Downstream PRs (will be copied)

container: add support for gvnic to `google_container_node_pool`

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 4 files changed, 105 insertions(+), 2 deletions(-))
Terraform Beta: Diff ( 4 files changed, 105 insertions(+), 2 deletions(-))
TF Validator: Diff ( 2 files changed, 3 insertions(+), 3 deletions(-))

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccDatasourceGoogleServiceNetworkingPeeredDnsDomain_basic|TestAccDataSourceSqlDatabaseInstance_basic|TestAccBigqueryReservationAssignment_BasicHandWritten|TestAccCGCSnippet_sqlSqlserverInstanceAuthorizedNetworkExample|TestAccCloudBuildTrigger_cloudbuildTriggerPubsubConfigExample|TestAccCloudBuildTrigger_cloudbuildTriggerWebhookConfigExample|TestAccCloudBuildTrigger_cloudbuildTriggerManualExample|TestAccCloudBuildTrigger_cloudbuildTriggerFilenameExample|TestAccCloudBuildTrigger_cloudbuildTriggerBuildExample|TestAccCloudBuildTrigger_basic|TestAccCloudBuildTrigger_available_secrets_config|TestAccCloudBuildTrigger_cloudbuildTriggerServiceAccountExample|TestAccCloudBuildTrigger_disable|TestAccCloudBuildTrigger_fullStep|TestAccContainerCluster_withAuthenticatorGroupsConfig|TestAccContainerNodePool_gvnic|TestAccServiceNetworkingPeeredDNSDomain_basic You can view the result here: https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=264780

[modular-magician]

Tests failed during RECORDING mode: TestAccContainerCluster_withAuthenticatorGroupsConfig Please fix these to complete your PR

[slevenick]

Looks good!

[rileykarson]

@ScottSuarez does this close hashicorp/terraform-provider-google#10836?