Specify URI template of desired DNS-over-HTTPS resolver

The URI template of the desired DNS-over-HTTPS resolver. To specify multiple DNS-over-HTTPS resolvers, separate the corresponding URI templates with spaces. If you set 'DnsOverHttpsMode' (Control the mode of DNS-over-HTTPS) to "secure", then this policy must be set and can't be empty. If you set 'DnsOverHttpsMode' to "automatic" and this policy is set, then the URI templates specified are used. If you don't set this policy, then hardcoded mappings are used to attempt to upgrade the user's current DNS resolver to a DoH resolver operated by the same provider. If the URI template contains a dns variable, requests to the resolver use GET; otherwise, requests use POST. Incorrectly formatted templates will be ignored. Example value: https://dns.example.net/dns-query{?dns}