[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

test/Core.Test/Auth/Services/SsoConfigServiceTests.cs

@@ -1,8 +1,10 @@
 using Bit.Core.AdminConsole.Entities;
 using Bit.Core.AdminConsole.Enums;
+using Bit.Core.AdminConsole.Models.Data;
 using Bit.Core.AdminConsole.Models.Data.Organizations.Policies;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies;
 using Bit.Core.AdminConsole.OrganizationFeatures.Policies.Models;
+using Bit.Core.AdminConsole.OrganizationFeatures.Policies.PolicyUpdateEvents.Interfaces;
 using Bit.Core.AdminConsole.Repositories;
 using Bit.Core.Auth.Entities;
 using Bit.Core.Auth.Enums;
@@ -12,6 +14,7 @@ using Bit.Core.Auth.Services;
 using Bit.Core.Exceptions;
 using Bit.Core.Models.Data.Organizations.OrganizationUsers;
 using Bit.Core.Repositories;
+using Bit.Core.Services;
 using Bit.Test.Common.AutoFixture;
 using Bit.Test.Common.AutoFixture.Attributes;
 using NSubstitute;
@@ -364,4 +367,54 @@ public class SsoConfigServiceTests
         await sutProvider.GetDependency<ISsoConfigRepository>().ReceivedWithAnyArgs()
             .UpsertAsync(default);
     }
+
+    [Theory, BitAutoData]
+    public async Task SaveAsync_Tde_WhenPolicyValidatorsRefactorEnabled_UsesVNextSavePolicyCommand(
+        SutProvider<SsoConfigService> sutProvider, Organization organization)
+    {
+        var ssoConfig = new SsoConfig
+        {
+            Id = default,
+            Data = new SsoConfigurationData
+            {
+                MemberDecryptionType = MemberDecryptionType.TrustedDeviceEncryption,
+            }.Serialize(),
+            Enabled = true,
+            OrganizationId = organization.Id,
+        };
+
+        sutProvider.GetDependency<IFeatureService>()
+            .IsEnabled(FeatureFlagKeys.PolicyValidatorsRefactor)
+            .Returns(true);
+
+        await sutProvider.Sut.SaveAsync(ssoConfig, organization);
+
+        await sutProvider.GetDependency<IVNextSavePolicyCommand>()
+            .Received(1)
+            .SaveAsync(Arg.Is<SavePolicyModel>(m =>
+                m.PolicyUpdate.Type == PolicyType.SingleOrg &&
+                m.PolicyUpdate.OrganizationId == organization.Id &&
+                m.PolicyUpdate.Enabled &&
+                m.PerformedBy is SystemUser));
+
+        await sutProvider.GetDependency<IVNextSavePolicyCommand>()
+            .Received(1)
+            .SaveAsync(Arg.Is<SavePolicyModel>(m =>
+                m.PolicyUpdate.Type == PolicyType.ResetPassword &&
+                m.PolicyUpdate.GetDataModel<ResetPasswordDataModel>().AutoEnrollEnabled &&
+                m.PolicyUpdate.OrganizationId == organization.Id &&
+                m.PolicyUpdate.Enabled &&
+                m.PerformedBy is SystemUser));
+
+        await sutProvider.GetDependency<IVNextSavePolicyCommand>()
+            .Received(1)
+            .SaveAsync(Arg.Is<SavePolicyModel>(m =>
+                m.PolicyUpdate.Type == PolicyType.RequireSso &&
+                m.PolicyUpdate.OrganizationId == organization.Id &&
+                m.PolicyUpdate.Enabled &&
+                m.PerformedBy is SystemUser));
+
+        await sutProvider.GetDependency<ISsoConfigRepository>().ReceivedWithAnyArgs()
+            .UpsertAsync(default);
+    }
 }