Cleanup /var/crash dir before ami creation

Signed-off-by: Francesco De Martino <fdm@amazon.com>

Author: demartinofra

files/default/ami_cleanup.sh

@@ -6,6 +6,7 @@ rm -f /var/lib/cloud/instance
 rm -rf /etc/ssh/ssh_host_*
 rm -f /etc/udev/rules.d/70-persistent-net.rules
 grep -l "Created by cloud-init on instance boot automatically" /etc/sysconfig/network-scripts/ifcfg-* | xargs rm -f
+rm -rf /var/crash/*
 
 # https://bugs.centos.org/view.php?id=13836#c33128
 source /etc/os-release