V8: Update lkgr config.
V8: Update lkgr config.

BUG=498689
TBR=sergiyb@chromium.org

Review URL: https://codereview.chromium.org/1176793004

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra