[DOCKER] Fix various cron issues (#1204)
Closes
- #1200
- Runs in the background now
- #1201
- Was not running as user
abc
, now it is
- Was not running as user
- #1202
- Due to reading stdout and tail of hidden log file. Should only tail from hidden log file now
Will leave crontab as-is if no CRON_SCHEDULE is specified