Description of problem:
Foreman-maintain upgrade run failed during upgrade because it tried to start local postgresql service when remote DB is used.

Version-Release number of selected component (if applicable):
Origin: satellite-6.5.2-1.el7sat.noarch

Upgrade to: Satellite 6.6.0 snap 13

How reproducible:
always

Steps to Reproduce:
1. Have Satellite set up using all external DB with SSL
2. Run foreman-maintain upgrade

Actual results:
Upgrade fails.
.
.
.
foreman-maintain service stop finished successfully!
Upgrade Step: start_postgresql...
Failed to start postgresql.service: Unit not found.
systemctl start postgresql failed! Check the output for error!
Upgrade step start_postgresql failed. Check logs for more information.
                                      [FAIL]
Failed executing LANG=en_US.utf-8 satellite-installer --upgrade, exit status 1
--------------------------------------------------------------------------------
Scenario [Migration scripts to Satellite 6.6] failed.

The following steps ended up in failing state:

  [installer-upgrade]

Resolve the failed steps and rerun
the command. In case the failures are false positives,
use --whitelist="installer-upgrade"


Expected results:
Upgrade finished successfully.

Additional info:
Upgrade finished successfully after whitelisting [installer-upgrade] step.

# foreman-maintain service status
Running Status Services
================================================================================
Get status of applicable services: 
Displaying the following service(s):

rh-mongodb34-mongod, postgresql (foreman), postgresql (candlepin), qdrouterd, qpidd, squid, pulp_celerybeat, pulp_resource_manager, pulp_streamer, pulp_workers, smart_proxy_dynflow_core, tomcat, dynflowd, httpd, puppetserver, foreman-proxy
\ displaying rh-mongodb34-mongod                                                
rh-mongodb34-mongod is remote and is UP.
\ displaying postgresql (foreman)                                               
postgresql (foreman) is remote and is UP.
| displaying postgresql (candlepin)                                             
postgresql (candlepin) is remote and is UP.