Bug with azure-quickstart-templates - 201-vmss-linux-nat template

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azure-quickstart-templates/201-vmss-linux-nat template

### Issue Details

Template variable newStorageAccountSuffix uses namingInfix variable which comes from the VMSS name.
This is a problem because if I choose a VMSS with a name that has a "-" character, the deployment fails because the "-" character will be inherited by the namingInfix and then end up in the newStorageAccountSuffix. The newStorageAccountSuffix variable cannot have a "-" because storage account creation will fail with message : "xxxx-xxxx is not a valid storage account name. Storage account name must be between 3 and 24 characters in length and use numbers and lower-case letters only.

To reproduce, try deploying this template and have a VMSS name that has a "-" character in its name.

Start with the azure-quickstart-templates/201-vmss-linux-nat template and inspect how namingInfix is used to form newStorageAccountSuffix. Reproduce the deployment with a VMSS name containing a hyphen, then verify that the generated storage account name uses only permitted characters and the deployment succeeds.

Written by the indexing model from the issue text.