Enums entries missing extension `x-ms-enum`

We have some swaggers that are missing `x-ms-enum` extension. For instance, this: https://github.com/Azure/azure-rest-api-specs/blob/ff541d84da3e56318de42e92222e9501a9ccb632/specification/compute/resource-manager/Microsoft.ContainerService/stable/2017-01-31/containerService.json#L359
In code generation, a code-name with number will be given to this enum type (for instance `Enum47`), and during the update of the swaggers, this code-name might change and cause unnecessary breaking changes.

Related issue: https://github.com/Azure/autorest.go/issues/571

Start by inspecting specification/compute/resource-manager/Microsoft.ContainerService/stable/2017-01-31/containerService.json around line 359 and compare the enum declaration with the requested x-ms-enum extension. Search the Swagger specifications for other enum entries with the same omission, then verify that code generation no longer assigns unstable numeric names such as Enum47.

Written by the indexing model from the issue text.