override docker service so systemd:
1. to create/remove /var/run/dockerd.pid file at service start/stop.
2. not to restart automatically on exit or failure
deploy docker.conf for pmond to monitor docker service
Story: 2002843
Task: 29391
Change-Id: I3595d0d4f97d90e4119fc1455bcf164aebc5d6ec
Signed-off-by: Bin Qian <bin.qian@windriver.com>