fix: test_os_svc_daemon.py

Since I6487d0726db08912eed3062dfee2552940eadcfb, a ExecStartPre call
is added in the systemd .service file.
This patch adjust test_os_svc_daemon.py.

For the record, the remaining PEP8 error is fixed in
If5068ef77d6643c19de36bfcf4b4bf790f86b538.

Change-Id: I9b1859f9fc5846c7c42606644231105618e1a1a0
Merge "fix: test_os_svc_daemon.py"