Cause node pool to be written to statefile even if creation fails.

[nat-henderson]

Fixes hashicorp/terraform-provider-google#6287.

Release Note Template for Downstream PRs (will be copied)

container: Fix occasional error with `container_node_pool` partially-successful creations not being recorded if an error occurs on the GCP side.

[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, 5 insertions(+), 2 deletions(-))
Terraform Beta: Diff ( 1 file changed, 5 insertions(+), 2 deletions(-))

[nat-henderson]

Running the tests, will take a while.

[nat-henderson]

Tests pass!