Parameter 'dataDisk.name' is not allowed

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[Template Name goes here](Template link goes here)

### Issue Details
Trying to deploy VMSS resource with managed disk,
I am trying to setup disk name and receiving following error

New-AzureRmResourceGroupDeployment : 1:37:34 PM - Resource Microsoft.Resources/deployments 'VmssDeployment' failed
with message '{
"status": "Failed",
"error": {
"code": "ResourceDeploymentFailure",
"message": "The resource operation completed with terminal provisioning state 'Failed'.",
"details": [
{
"code": "DeploymentFailed",
"message": "At least one resource deployment operation failed. Please list deployment operations for details.
Please see https://aka.ms/arm-debug for usage details.",
"details": [
{
"code": "BadRequest",
"message": "{\r\n \"error\": {\r\n \"code\": \"InvalidParameter\",\r\n \"message\": \"Parameter
'dataDisk.name' is not allowed.\",\r\n \"target\": \"dataDisk.name\"\r\n }\r\n}"
},
{
"code": "BadRequest",
"message": "{\r\n \"error\": {\r\n \"code\": \"InvalidParameter\",\r\n \"message\": \"Parameter
'dataDisk.name' is not allowed.\",\r\n \"target\": \"dataDisk.name\"\r\n }\r\n}"
}
]
}
]
}
}'

### Repro steps (*if necessary, delete otherwise*)
1. Create VMSS with following disks section with manged disk
"dataDisks": [
{
"lun": 0,
**"name": "mydisk",**
"diskSizeGB": "[parameters('nodeType1ManagedDiskSizeInGB')]",
"createOption": "Empty",
"caching": "[parameters('nodeType1ManagedDiskCaching')]",
"managedDisk": {
"storageAccountType": "[parameters('nodeType1ManagedDiskType')]"
}
}
]

2. "apiVersion": "2018-10-01",
"type": "Microsoft.Compute/virtualMachineScaleSets",
3. deploy arm template failed with above error.

NOTE: using following document.
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/using-managed-disks-template-deployments#managed-disks-template-formatting

Start with the VMSS dataDisks block in the ARM template and compare its managed-disk fields with the linked managed disks template documentation. Verify the behavior with the shown apiVersion 2018-10-01 and deployment steps; done means the template deploys without the dataDisk.name InvalidParameter error.

Written by the indexing model from the issue text.