Regen for abstract base class

[Yao725]

Part of https://github.com/Azure/autorest.csharp/pull/2520

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[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

Azure.ResourceManager.Media Azure.ResourceManager.MachineLearning Azure.ResourceManager.Monitor Azure.ResourceManager.ContainerRegistry Azure.ResourceManager.EdgeOrder Azure.ResourceManager.AlertsManagement Azure.ResourceManager.PostgreSql Azure.ResourceManager.StreamAnalytics Azure.ResourceManager.ServiceFabric Azure.ResourceManager.DataFactory Azure.ResourceManager.Workloads Azure.ResourceManager.Migrate Azure.ResourceManager.AppPlatform Azure.ResourceManager.Authorization Azure.ResourceManager.MySql Azure.ResourceManager.ServiceLinker Azure.ResourceManager.CosmosDB Azure.ResourceManager.ResourceMover