101-vms-with-selfhost-integration-runtime template erroring when deploying to UK South due to VM size unavailibility

[101-vms-with-selfhost-integration-runtime] (https://github.com/Azure/azure-quickstart-templates/tree/master/101-vms-with-selfhost-integration-runtime)

### Issue Details
Unable to deploy as the VM size is unavailable in UK South - please refer to the below error message. Could the template be modified so that the size of the VM could be parameterized?

The template deployment failed with error: 'The resource with id: '/subscriptions/8d4b64d2-ac50-46ae-b070-c052a7d96bdc/resourceGroups/DataLakePOC/providers/Microsoft.Compute/virtualMachines/vm0-Integration' failed validation with message: 'The requested size for resource '/subscriptions/8d4b64d2-ac50-46ae-b070-c052a7d96bdc/resourceGroups/DataLakePOC/providers/Microsoft.Compute/virtualMachines/vm0-Integration' is currently not available in location 'UK South' zones '' for subscription '8d4b64d2-ac50-46ae-b070-c052a7d96bdc'. Please try another size or deploy to a different location or zones. See https://aka.ms/azureskunotavailable for details.'.'. (Code: InvalidTemplateDeployment)

Start in the 101-vms-with-selfhost-integration-runtime template directory and locate where the VM size is set. Check how the template defines deployment parameters, then make the VM size configurable and verify that the template can be deployed with a size available in UK South.

Written by the indexing model from the issue text.