Use "module" instead of "regex" when updating "CreateMappings_rules.json"

When moving a new module from generation to main we update `CreateMappings_rules.json` to add a new entry like this:

```json
{
"regex": "DnsResolver",
"alias": "DnsResolver"
}
```

However it is discouraged to use "regex" because Azure PowerShell have so many modules and cmdlets and their names are easy to overlap each other. The recommended way is to use "module".