Automatic merge from submit-queue
Update GCI_VERSION to gci-dev-55-8866-0-0
Update GCI base image:
Change log:
* Built-in kubernetes updated to v1.4.0
* Enabled VXLAN and IP_SET config options in kernel to support some networking tools
* OpenSSL CVE fixes
```release-note
Update GCI base image:
* Enabled VXLAN and IP_SET config options in kernel to support some networking tools (ebtools)
* OpenSSL CVE fixes
```
cc/ @kubernetes/goog-image cc/ @dchen1107