Install Guide: Readd Debian Config changes

A recent patch reverted by accident these changes to mark some
sections Debian only.

Re-add

Change-Id: I3a7e08736940337d2595c4fca9f2baf322a5fa2f
backport: havana
(cherry picked from commit c6b327074a726f079fad638669141275b3f2cbd1)