Modify the NetworkManager codebase to enable Duplicate Address Detection by default for manual IP addresses and determine a suitable timeout for the DAD process.

Acceptance criteria:

Given a system with NetworkManager installed and an existing configuration,

When the user upgrades NetworkManager to the new version with the changed default DAD behavior,

Then the default value of ipv4.dad-timeout should be automatically changed to 3000ms, enabling DAD for all static and DHCP addresses by default.

Given a system with NetworkManager installed and DAD enabled by default for both static and DHCP addresses,

When a user connects to a network with multiple addresses and at least one of them has a conflict,

Then NetworkManager should log a warning and configure only the non-conflicting addresses, allowing the connection activation to proceed.

Given a system with NetworkManager installed and DAD enabled by default,

When a user checks the device information using nmcli,

Then nmcli should display conflicting addresses alongside the non-conflicting addresses.

Definition of done:

• The implementation meets the acceptance criteria
• All the subtasks are done
• The code is part of a build attached to an errata