feat: add subnetwork enable_flow_logs field

[Dawid212]

This pr adds enable_flow_logs field to subnetwork resource

compute: add `enable_flow_logs` field to `google_compute_subnetwork` resource

[github-actions]

Hello! I am a robot. Tests will require approval from a repository maintainer to run.

Googlers: For automatic test runs see go/terraform-auto-test-runs.

@BBBmau, a repository maintainer, has been assigned to review your changes. If you have not received review feedback within 2 business days, please leave a comment on this PR asking them to take a look.

You can help make sure that review is quick by doing a self-review and by running impacted tests locally.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 4 files changed, 108 insertions(+))
google-beta provider: Diff ( 4 files changed, 108 insertions(+))
terraform-google-conversion: Diff ( 4 files changed, 35 insertions(+))
Open in Cloud Shell: Diff ( 1 file changed, 2 insertions(+))

[modular-magician]

Tests analytics

Total tests: 1318
Passed tests: 1231
Skipped tests: 84
Affected tests: 3

Click here to see the affected service packages

• compute

Action taken

Found 3 affected test(s) by replaying old test recordings. Starting RECORDING based on the most recent commit. Click here to see the affected tests

• TestAccComputeFutureReservation_sharedFutureReservationExample
• TestAccComputeRegionBackendService_regionBackendServiceHaPolicyManualLeader_update
• TestAccComputeSubnetwork_subnetworkLoggingConfigExample

Get to know how VCR tests work

[modular-magician]

🟢 Tests passed during RECORDING mode:
TestAccComputeRegionBackendService_regionBackendServiceHaPolicyManualLeader_update [Debug log]
TestAccComputeSubnetwork_subnetworkLoggingConfigExample [Debug log]

🔴 Tests failed when rerunning REPLAYING mode:
TestAccComputeRegionBackendService_regionBackendServiceHaPolicyManualLeader_update [Error message] [Debug log]

Tests failed due to non-determinism or randomness when the VCR replayed the response after the HTTP request was made.

Please fix these to complete your PR. If you believe these test failures to be incorrect or unrelated to your change, or if you have any questions, please raise the concern with your reviewer.

---

🔴 Tests failed during RECORDING mode:
TestAccComputeFutureReservation_sharedFutureReservationExample [Error message] [Debug log]

🔴 Errors occurred during RECORDING mode. Please fix them to complete your PR.

View the build log or the debug log for each test

[BBBmau]

TestAccComputeFutureReservation_sharedFutureReservationExample is a flaky test and can be ignored.

TestAccComputeRegionBackendService_regionBackendServiceHaPolicyManualLeader_update is consistently passing in TC, we'll rerun this once the comment is addressed.

[BBBmau]

when we have send_empty_value: true simultaneously with default_from_api: true it only sends an empty value if it's explicitly set in config. We may want to remove this since when unset it would continue to use the default_from_api which looks to be false as it's a boolean.