debian: Fixup ACRN lifemngr package build

Part of fix for
https://github.com/tttech-industrial-buchsbaum/acrn-hypervisor/issues/6

Tracked-On: #6688
Signed-off-by: Helmut Buchsbaum <helmut.buchsbaum@opensource.tttech-industrial.com>

debian/acrn-lifemngr.postrm

@@ -0,0 +1,46 @@
+#!/bin/sh
+# postrm script for grub-acrn
+#
+# see: dh_installdeb(1)
+
+set -e
+
+# summary of how this script can be called:
+#        * <postrm> `remove'
+#        * <postrm> `purge'
+#        * <old-postrm> `upgrade' <new-version>
+#        * <new-postrm> `failed-upgrade' <old-version>
+#        * <new-postrm> `abort-install'
+#        * <new-postrm> `abort-install' <old-version>
+#        * <new-postrm> `abort-upgrade' <old-version>
+#        * <disappearer's-postrm> `disappear' <overwriter>
+#          <overwriter-version>
+# for details, see https://www.debian.org/doc/debian-policy/ or
+# the debian-policy package
+
+
+case "$1" in
+    remove|purge)
+        # remove any preinstalled & unchanged configfile
+        if cmp -s "/etc/life_mngr/life_mngr.conf" "/usr/share/acrn-lifemngr/life_mngr.conf.service_vm" || \
+           cmp -s "/etc/life_mngr/life_mngr.conf" "/usr/share/acrn-lifemngr/life_mngr.conf.user_vm" ; then
+            rm -f /etc/life_mngr/life_mngr.conf
+            # also remove an empty config directory
+            [ "$(ls -A /etc/life_mngr)" ] && rm -rf /etc/life_mngr
+        fi
+    ;;
+    upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)
+    ;;
+
+    *)
+        echo "postrm called with unknown argument \`$1'" >&2
+        exit 1
+    ;;
+esac
+
+# dh_installdeb will replace this with shell code automatically
+# generated by other debhelper scripts.
+
+#DEBHELPER#
+
+exit 0