iam_binding: set ResourceIdentity when members are nil

[BBBmau]

ResourceIdentity was only being set when matching binding was found, leaving the case of noMembers not covered resulting in missing identity error in VCR. This resolves the failing test we see currently:

Error recording tests:
error running go: exit status 1
stdout:
=== RUN   TestAccProjectIamBinding_noMembers
=== PAUSE TestAccProjectIamBinding_noMembers
=== CONT  TestAccProjectIamBinding_noMembers
    resource_google_project_iam_binding_test.go:231: Step 3/3 error running import: exit status 1
        
        Error: Missing Resource Identity After Read: The Terraform provider unexpectedly returned no resource identity after having no errors in the resource read. This is always a problem with the provider and should be reported to the provider developer
        
        
--- FAIL: TestAccProjectIamBinding_noMembers (61.63s)
FAIL
FAIL	github.com/hashicorp/terraform-provider-google-beta/google-beta/services/resourcemanager	61.709s
FAIL
stderr:

follow-up to #17587

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[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes for commit 1799859:

Diff report

Your PR generated the following diffs in downstream repositories:

Repository	Diff Link	Changes
google provider	View Diff	1 file changed, 11 insertions(+)
google-beta provider	View Diff	1 file changed, 11 insertions(+)

Test report

Analytics

Total Tests	Passed	Skipped	Affected
6459	5788	659	12

Affected Service Packages

• All service packages are affected

Learn how VCR tests work

---

Step 1: Replaying Mode

Action taken

Found 12 affected test(s) by replaying old test recordings. Starting RECORDING based on the most recent commit.

Click here to see the affected tests

• TestAccBeyondcorpAppConnection_beyondcorpAppConnectionBasicExample
• TestAccCloudRunService_cloudRunServiceGpuExample
• TestAccComputeRouterPeer_AddMd5AuthenticationKey
• TestAccContainerNodePool_withHostMaintenancePolicy
• TestAccDataformConfig_update
• TestAccDataformRepository_dataformRepositoryWithCloudsourceRepoAndSshExample
• TestAccDataprocMetastoreService_dataprocMetastoreServicePrivateServiceConnectExample
• TestAccDiscoveryEngineDataStore_discoveryengineDatastoreKmsKeyNameExample
• TestAccIapWebTypeAppEngineIamMemberGenerated
• TestAccManagedKafkaConnector_managedkafkaConnectorBasicExample
• TestAccPubsubSubscription_pubsubSubscriptionTagsExample
• TestAccSourceRepoRepositoryIamMemberGenerated

View the replaying VCR build log

---

Step 2: Recording Mode

Recording Mode	Replaying Rerun	Test Name
✅ Log	❌ Error · Log	TestAccComputeRouterPeer_AddMd5AuthenticationKey
✅ Log	❌ Error · Log	TestAccDataformConfig_update
❌ Error · Log	-	TestAccBeyondcorpAppConnection_beyondcorpAppConnectionBasicExample
❌ Error · Log	-	TestAccCloudRunService_cloudRunServiceGpuExample
❌ Error · Log	-	TestAccContainerNodePool_withHostMaintenancePolicy
❌ Error · Log	-	TestAccDataformRepository_dataformRepositoryWithCloudsourceRepoAndSshExample
❌ Error · Log	-	TestAccDataprocMetastoreService_dataprocMetastoreServicePrivateServiceConnectExample
❌ Error · Log	-	TestAccDiscoveryEngineDataStore_discoveryengineDatastoreKmsKeyNameExample
❌ Error · Log	-	TestAccIapWebTypeAppEngineIamMemberGenerated
❌ Error · Log	-	TestAccManagedKafkaConnector_managedkafkaConnectorBasicExample
❌ Error · Log	-	TestAccPubsubSubscription_pubsubSubscriptionTagsExample
❌ Error · Log	-	TestAccSourceRepoRepositoryIamMemberGenerated

Caution

Issues requiring attention before PR completion

🔴 Initial Recording Failed: Some tests failed during the recording step. See the table above for details.

🔴 Replaying Rerun Failed: Some tests failed due to non-determinism when VCR replayed the response. See the table above for details.

Please address these issues to complete your PR. If you believe these detections are incorrect or unrelated to your change, please raise the concern with your reviewer.

View the recording VCR build log or the debug logs folder for detailed results.

@BBBmau, @trodge VCR tests complete for 1799859!