[PM-26690] Wire VNextSavePolicyCommand behind PolicyValidatorsRefactor feature flag (#6483)

* Add PolicyValidatorsRefactor constant to FeatureFlagKeys in Constants.cs

* Add Metadata property and ToSavePolicyModel method to PolicyUpdateRequestModel

* Refactor PoliciesController to utilize IVNextSavePolicyCommand based on feature flag

- Added IFeatureService and IVNextSavePolicyCommand dependencies to PoliciesController.
- Updated PutVNext method to conditionally use VNextSavePolicyCommand or SavePolicyCommand based on the PolicyValidatorsRefactor feature flag.
- Enhanced unit tests to verify behavior for both enabled and disabled states of the feature flag.

* Update public PoliciesController to to utilize IVNextSavePolicyCommand based on feature flag

- Introduced IFeatureService and IVNextSavePolicyCommand to manage policy saving based on the PolicyValidatorsRefactor feature flag.
- Updated the Put method to conditionally use the new VNextSavePolicyCommand or the legacy SavePolicyCommand.
- Added unit tests to validate the behavior of the Put method for both enabled and disabled states of the feature flag.

* Refactor VerifyOrganizationDomainCommand to utilize IVNextSavePolicyCommand based on feature flag

- Added IFeatureService and IVNextSavePolicyCommand dependencies to VerifyOrganizationDomainCommand.
- Updated EnableSingleOrganizationPolicyAsync method to conditionally use VNextSavePolicyCommand or SavePolicyCommand based on the PolicyValidatorsRefactor feature flag.
- Enhanced unit tests to validate the behavior when the feature flag is enabled.

* Enhance SsoConfigService to utilize IVNextSavePolicyCommand based on feature flag

- Added IFeatureService and IVNextSavePolicyCommand dependencies to SsoConfigService.
- Updated SaveAsync method to conditionally use VNextSavePolicyCommand or SavePolicyCommand based on the PolicyValidatorsRefactor feature flag.
- Added unit tests to validate the behavior when the feature flag is enabled.

* Refactor SavePolicyModel to simplify constructor usage by removing EmptyMetadataModel parameter. Update related usages across the codebase to reflect the new constructor overloads.

* Update PolicyUpdateRequestModel to make Metadata property nullable for improved null safety

src/Core/AdminConsole/OrganizationFeatures/OrganizationDomains/VerifyOrganizationDomainCommand.cs

@@ -6,6 +6,7 @@ using Bit.Core.AdminConsole.Models.Data;
 using Bit.Core.AdminConsole.OrganizationFeatures.OrganizationDomains.Interfaces;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies.Models;
+using Bit.Core.AdminConsole.OrganizationFeatures.Policies.PolicyUpdateEvents.Interfaces;
 using Bit.Core.Context;
 using Bit.Core.Entities;
 using Bit.Core.Enums;
@@ -24,7 +25,9 @@ public class VerifyOrganizationDomainCommand(
     IEventService eventService,
     IGlobalSettings globalSettings,
     ICurrentContext currentContext,
+    IFeatureService featureService,
     ISavePolicyCommand savePolicyCommand,
+    IVNextSavePolicyCommand vNextSavePolicyCommand,
     IMailService mailService,
     IOrganizationUserRepository organizationUserRepository,
     IOrganizationRepository organizationRepository,
@@ -131,15 +134,26 @@ public class VerifyOrganizationDomainCommand(
         await SendVerifiedDomainUserEmailAsync(domain);
     }
 
-    private async Task EnableSingleOrganizationPolicyAsync(Guid organizationId, IActingUser actingUser) =>
-        await savePolicyCommand.SaveAsync(
-            new PolicyUpdate
-            {
-                OrganizationId = organizationId,
-                Type = PolicyType.SingleOrg,
-                Enabled = true,
-                PerformedBy = actingUser
-            });
+    private async Task EnableSingleOrganizationPolicyAsync(Guid organizationId, IActingUser actingUser)
+    {
+        var policyUpdate = new PolicyUpdate
+        {
+            OrganizationId = organizationId,
+            Type = PolicyType.SingleOrg,
+            Enabled = true,
+            PerformedBy = actingUser
+        };
+
+        if (featureService.IsEnabled(FeatureFlagKeys.PolicyValidatorsRefactor))
+        {
+            var savePolicyModel = new SavePolicyModel(policyUpdate, actingUser);
+            await vNextSavePolicyCommand.SaveAsync(savePolicyModel);
+        }
+        else
+        {
+            await savePolicyCommand.SaveAsync(policyUpdate);
+        }
+    }
 
     private async Task SendVerifiedDomainUserEmailAsync(OrganizationDomain domain)
     {

src/Core/AdminConsole/OrganizationFeatures/Policies/Models/SavePolicyModel.cs

@@ -5,4 +5,18 @@ namespace Bit.Core.AdminConsole.OrganizationFeatures.Policies.Models;
 
 public record SavePolicyModel(PolicyUpdate PolicyUpdate, IActingUser? PerformedBy, IPolicyMetadataModel Metadata)
 {
+    public SavePolicyModel(PolicyUpdate PolicyUpdate)
+        : this(PolicyUpdate, null, new EmptyMetadataModel())
+    {
+    }
+
+    public SavePolicyModel(PolicyUpdate PolicyUpdate, IActingUser performedBy)
+        : this(PolicyUpdate, performedBy, new EmptyMetadataModel())
+    {
+    }
+
+    public SavePolicyModel(PolicyUpdate PolicyUpdate, IPolicyMetadataModel metadata)
+        : this(PolicyUpdate, null, metadata)
+    {
+    }
 }