The MountTargets property shouldn't be interface{} in azure-sdk-for-go

[neil-yechenwei]

The property type of “MountTargets” is “interface{}” not exact data type not like property “ExportPolicy” in azure-sdk-for-go (https://github.com/Azure/azure-sdk-for-go/blob/ef852a52f96b87fc7c4912888e0f286b6455ef05/services/netapp/mgmt/2019-11-01/netapp/models.go#L1517). So we have to parse the property “MountTargets” with below complex way. As I know, the code in azure-sdk-for-go is auto generated by the azure-rest-api-spec. So I think maybe there is some problem in the azure-rest-api-spec for this property “MountTargets”. So could you make a fix to set the property “MountTargets” as exact data type like ExportPolicy in azure-rest-api-spec (https://github.com/Azure/azure-rest-api-specs/blob/master/specification/netapp/resource-manager/Microsoft.NetApp/stable/2019-11-01/netapp.json)?

Current way to parse the property “MountTargets” with azure-sdk-for-go:

[neil-yechenwei]

@leonardbf , may I know when the fix for this issue can be released in azure-sdk-for-go since we're blocked now?