Use oem-config-prepare package

Remove this hook; it's only for pre-installed desktop images and
8fb2180842 already removed the other bits
for pre-installed desktop images.

live-build/ubuntu/hooks/099-ubuntu-image-customization.chroot

@@ -1,54 +0,0 @@
-#!/bin/bash -ex
-
-. /root/config/chroot
-
-# Specific ubuntu-image chroot configuration goes here.
-if [ "$IMAGEFORMAT" == "none" ]; then
-    if [ "$SUBPROJECT" == "desktop-preinstalled" ]; then
-        # Create files/dirs Ubiquity requires
-        mkdir -p /var/log/installer
-        touch /var/log/installer/debug
-        touch /var/log/syslog
-        chown syslog:adm /var/log/syslog
-
-        # Create the oem user account only if it doesn't already exist
-        if ! id "oem" &>/dev/null; then
-                /usr/sbin/useradd -d /home/oem -G adm,sudo -m -N -u 29999 oem
-                /usr/sbin/oem-config-prepare --quiet
-                touch "/var/lib/oem-config/run"
-        fi
-
-        # Update the fstab to include the "discard" option
-        awk \
-            -v root_fs_label="writable" \
-            -v root_fs_options="discard" \
-            '
-        BEGIN { OFS="\t"; count=0; }
-
-        # Omit the "UNCONFIGURED" warning if it is still present
-        /^# UNCONFIGURED FSTAB/ { next; }
-
-        # Only modify the first non-comment line where the second field is the
-        # root and omit multiple root definitions
-        /^[^#]/ && $2 == "/" {
-            if (!count) {
-                $1="LABEL=" root_fs_label;
-                $4=root_fs_options;
-                $6="1";
-            }
-            count++;
-            if (count > 1) next;
-        }
-
-        { print; }
-
-        # If we reach the end without seeing a root mount line, add one
-        END {
-            if (!count) {
-                print "LABEL=" root_fs_label, "/", "ext4", root_fs_options, "0", "1";
-            }
-        }
-        ' /etc/fstab > /etc/fstab.new
-        mv /etc/fstab.new /etc/fstab
-    fi
-fi