Remove apt lists that are currently removed downstream anyway.

(LP: #1699913)

debian/changelog

@@ -3,6 +3,8 @@ livecd-rootfs (2.529~ppa2~manpages1) cosmic; urgency=medium
   * Improvements to the ubuntu-base (i.e. Docker) build:
     - Customize the unminimize script to not install so many packages.
     - Divert /usr/bin/man to a script that points to the unminimize script.
+    - Remove apt lists that are currently removed downstream anyway. 
+      (LP: #1699913)
 
  -- Michael Hudson-Doyle <michael.hudson@ubuntu.com>  Tue, 05 Jun 2018 14:19:17 +1200
 

live-build/auto/build

@@ -261,6 +261,11 @@ EOF
 	# remove crufty files that shouldn't be left in an image
 	rm -f chroot/var/cache/debconf/*-old chroot/var/lib/dpkg/*-old
 	Chroot chroot apt clean
+	if [ "${PROJECT}:${SUBPROJECT:-}" = "ubuntu-base:minimized" ]; then
+		# Save even more size by removing apt lists (that are currently removed
+		# downstream anyway)
+		rm -f chroot/var/lib/apt/lists/*
+	fi
 
 	if [ -f config/oem-config-preinstalled ]; then