message: add back ManagedDatabaseRestoreDetails specs
diff: @@ -116,6 +116,7 @@ input-file:
  - Microsoft.Sql/preview/2019-06-01-preview/syncGroups.json
  - Microsoft.Sql/preview/2019-06-01-preview/syncMembers.json
  - Microsoft.Sql/preview/2020-02-02-preview/ManagedDatabases.json
  +- Microsoft.Sql/preview/2020-02-02-preview/ManagedDatabaseRestoreDetails.json
  - Microsoft.Sql/preview/2020-02-02-preview/ServerAzureADOnlyAuthentications.json
  - Microsoft.Sql/preview/2020-02-02-preview/ManagedInstances.json
  - Microsoft.Sql/preview/2020-02-02-preview/ManagedInstanceAzureADOnlyAuthentications.json
  