201-vmss-scale-existing: Updated azuredeploy.parameters.json to accept prereqs outputs

[PraveenAnil]

Best Practice Checklist

Check these items before submitting a PR... See the Contribution Guide for the full detail: https://github.com/Azure/azure-quickstart-templates/blob/master/1-CONTRIBUTION-GUIDE/README.md

1. uri's compatible with all clouds (Stack, China, Government)
2. Staged artifacts use _artifactsLocation & _artifactsLocationSasToken
3. Use resourceGroup().location for resource locations
4. Folder names for artifacts (nestedtemplates, scripts, DSC)
5. Use literal values for apiVersion (no variables)
6. Parameter files (GEN-UNIQUE for value generation and no "changemeplease" values
7. $schema and other uris use https
8. Use uniqueString() whenever possible to generate names for resources. While this is not required, it's one of the most common failure points in a deployment.
9. Update the metadata.json with the current date

For details: https://github.com/Azure/azure-quickstart-templates/blob/master/1-CONTRIBUTION-GUIDE/bp-checklist.md

• - Please check this box once you've submitted the PR if you've read through the Contribution Guide and best practices checklist.

Changelog

[msftclas]

@PraveenAnil,
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Thanks,
Microsoft Pull Request Bot

[bmoore-msft]

let's update this to 2017-03-30

[bmoore-msft]

simplify with resourceId('Microsoft.Network/virtualNetworks/subnets, variables('virtualNetworkName'), variables('subnetName'))

[bmoore-msft]

I think you can just use existingVmss here... no need for uniqueString

[PraveenAnil]

Thanks for the feedback. I have updated the template with the suggested changes.