Nomad job log timestamps are in GMT

Issue Description

All the jobs started via nomad write the logs in GMT even though my system time is in IST

### Nomad version
nomad 0.8.4

### Operating system and Environment details
RHEL 7.3

### Issue
All the jobs started via nomad write the logs in GMT timestamp. When i run the service in standalone mode the logs are written with system time.

### Reproduction steps
There is no specific steps for the same. Any job started via nomad has this behaviour

### Job file
job "service1" {
region = "IN"
datacenters = ["dc1"]

task "service1" {
constraint {
attribute = "${attr.unique.network.ip-address}"
value = "x.x.x.x"
}
resources {
cpu = 500
memory = 2048
}
driver = "exec"
user = "appuser"

config {
command = "/bin/bash"
args = ["-c","cd /opt/service && /usr/lib/jvm/zulu-8/bin/java -Xms256m -Xmx2048m -XX:+HeapDumpOnOutOfMemoryError -jar service-${cs_version}.jar conf/dbconfig -Dhazelcast.config=/opt/service/conf/cache/hazelcast.xml"]
}

service {
name = "service"
tags = ["service"]
}
template {
data = <

No source file, test, or entry point is identified in the report. Start by tracing how Nomad formats logs for jobs versus standalone services, then compare timezone handling on RHEL; done means job logs use the expected system timezone rather than GMT.

Written by the indexing model from the issue text.