The chroot browsers have the wrong theme in camouflage mode

Originally created by @anonym on #9138 (Redmine)

While it doesn’t have the “red, scary” theme, it doesn’t have the Internet Explorer theme as expected, but GNOME’s default grey theme. This is a regression introduced in Tails 1.3, with the chroot browser refactoring.

Feature Branch: bugfix/9138-chroot-browser-camouflage

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information