Feature: Parameters config file should allow you to list by policy ID, not just display name

[kmcquade]

Notice how the Azure response says "The value '0' is not allowed for policy parameter 'minimumRSAKeySize' in policy definition 'cee51871-e572-4576-855c-047c820360f0'. The allowed values are '2048, 3072, 4096'."

If we allowed users to specify that policy ID, that could make their job a bit easier.

Error: creating Policy Set Definition "example_PR_Audit": policy.SetDefinitionsClient#CreateOrUpdate: Failure responding to request: StatusCode=400 -- Original Error: autorest/azure: Service returned an error. Status=400 Code="PolicyParameterValueNotAllowed" Message="The value '0' is not allowed for policy parameter 'minimumRSAKeySize' in policy definition 'cee51871-e572-4576-855c-047c820360f0'. The allowed values are '2048, 3072, 4096'."

  on main.tf line 257, in resource "azurerm_policy_set_definition" "example_PR_Audit":
 257: resource "azurerm_policy_set_definition" "example_PR_Audit" {