Added lubuntu-grub-theme and fonts
Summary: Added lubuntu-grub-theme and xfonts-efont-unicode
Test Plan: Check if lubuntu-grub-theme gets installed and selected automatically on a fresh installation.
Reviewers: kc2bez, tsimonq2, wxl, rikmills
Reviewed By: kc2bez, wxl
Differential Revision: https://phab.lubuntu.me/D68