ansible: Use full jinja2 variable syntax
ansible: Use full jinja2 variable syntax

Fixes the following deprecation warning:

> [DEPRECATION WARNING]: Using bare variables is deprecated. Update your
> playbooks so that the environment value uses the full variable syntax
> (`'{{ansible_interfaces}}'`). This feature will be removed in a future
> release. Deprecation warnings can be disabled by setting
> `deprecation_warnings=False` in ansible.cfg.

EasternEdgeRobotics/2016,EasternEdgeRobotics/2016,EasternEdgeRobotics/2016,EasternEdgeRobotics/2016