Automatic merge from submit-queue
GCI: Enable the log of upstart jobs
This PR enables the log of upstart jobs in master.yaml and node.yaml. By default, log of upstart jobs are enabled in Trusty and placed in /var/log/upstart, but not enabled in GCI. This change explicitly directs the log to the system logger. For trusty, they are in /var/log/syslog file. In GCI, we can check it using "journalctl". This change will be useful for debugging if cluster initialization fails.
@roberthbailey @maisem @dchen1107 please review it. This will be useful for issues like #23634. We should also cherry pick it in release-1.2
cc/ @fabioy @zmerlynn @wonderfly FYI.
ced2b65046