Automatic merge from submit-queue (batch tested with PRs 40971, 41027, 40709, 40903, 39369)

Bump GCI to gci-beta-56-9000-80-0

cc/ @Random-Liu @adityakali 

Changelogs since gci-dev-56-8977-0-0 (currently used in Kubernetes):
 - "net.ipv4.conf.eth0.forwarding" and "net.ipv4.ip_forward" may get reset to 0
 - Track CVE-2016-9962 in Docker in GCI
 - Linux kernel CVE-2016-7097
 - Linux kernel CVE-2015-8964
 - Linux kernel CVE-2016-6828
 - Linux kernel CVE-2016-7917
 - Linux kernel CVE-2016-7042
 - Linux kernel CVE-2016-9793
 - Linux kernel CVE-2016-7039 and CVE-2016-8666
 - Linux kernel CVE-2016-8655
 - Toolbox: allow docker image to be loaded from local tarball
 - Update compute-image-package in GCI 
 - Change the product name on /etc/os-release (to COS)
 - Remove 'dogfood' from HWID_OVERRIDE in /etc/lsb-release
 - Include Google NVME extensions to optimize LocalSSD performance.
 - /proc/<pid>/io missing on GCI (enables process stats accounting)
 - Enable BLK_DEV_THROTTLING

cc/ @roberthbailey @fabioy for GKE cluster update