Foreman Maintain

Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1867753

Description of problem:
Add a check for checkpoint_segments postgres parameter, so the installer does not fail on upgrade.

Version-Release number of selected component (if applicable):
satellite-6.8.0-0.7.beta.el7sat.noarch
satellite-installer-6.8.0.8-1.el7sat.noarch

Steps to Reproduce:
1. Have Sat 6.7 with /etc/foreman-installer/custom-hiera.yaml :
postgresql::server::config_entries:
checkpoint_segments: 32

2. Run upgrade to 6.8

Actual results:
Aug 8 16:18:34 pmoravec-sat-test sh: 2020-08-08 14:18:34.450 GMT [17329] LOG: unrecognized configuration parameter "checkpoint_segments" in file "/var/opt/rh/rh-postgresql12/lib/pgsql/data/postgresql.conf" line 760
Aug 8 16:18:34 pmoravec-sat-test sh: 2020-08-08 14:18:34.450 GMT [17329] FATAL: configuration file "/var/opt/rh/rh-postgresql12/lib/pgsql/data/postgresql.conf" contains errors
Aug 8 16:18:34 pmoravec-sat-test systemd: postgresql.service: main process exited, code=exited, status=1/FAILURE

Expected results:
a check saying either turn this off or to add to custom hiera.

Additional info:

This is based on BZ 1867311 reported by the installer. Ewoud says they should have to update their custom hiera to allow the upgrade to work:

https://bugzilla.redhat.com/show_bug.cgi?id=1867311#c2