Goal

• For global static servers configured in Network manager via global-dns-domain-* section, it should be possible to configure also encryption mode for specified servers.
• It already can specify servers, including name of expected certificate.
• No indication on global level can clearly indicate, TLS MUST be used for all specified servers. Not specified by each connection, but by global configuration.

Upstream issue: https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/1624

Acceptance criteria

A list of verification conditions, successful functional tests, or expected outcomes in order to declare this story/task successfully completed.

• Verify encrypted DNS can be specified for given domain
• Verify automatic mode can be configured (opportunistic), as well as enforced mode(yes) for given servers.
• Verify they are exposed over DBus GlobalDnsConfiguration property.