This patch disables ICMPv4 redirects feature on the host.
Accepting ICMP redirects has few legitimate uses.
It should be disabled unless it is absolutely required.
It is configurable by `security_disable_icmpv4_redirects`.
This feature is disabled by default as it can disrupt LXC deployments.
Change-Id: I228f8aa7b0df80cce16e54c5f1e11da678bfd67d