Bug 1664641

Description of problem:

it fails to restore backup what had been created before mongo storage engine was upgraded to wiredtiger

# foreman-maintain restore /tmp/backup-6.5/satellite-backup-2019-01-08-15-19-56/
Running Restore backup
...
--------------------------------------------------------------------------------
Restore configs from backup:
\ Restoring configs                                                   [OK]  
...
Run installer reset:
\ Installer reset                                                     [FAIL]   
Failed executing yes | satellite-installer -v --reset --disable-system-checks , exit status 6:
[ INFO 2019-01-08T16:42:08 verbose] Dropping Pulp database!
rm -f /var/lib/pulp/init.flag finished successfully!
systemctl stop httpd pulp_workers finished successfully!
Job for rh-mongodb34-mongod.service failed because the control process exited with error code. See "systemctl status rh-mongodb34-mongod.service" and "journalctl -xe" for details.
systemctl start rh-mongodb34-mongod failed! Check the output for error!
[ERROR 2019-01-08T16:42:08 verbose] systemctl start rh-mongodb34-mongod failed! Check the output for error!
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017/pulp_database
2019-01-08T16:42:08.847+0100 W NETWORK  [thread1] Failed to connect to 127.0.0.1:27017, in(checking socket for error after poll), reason: Connection refused
2019-01-08T16:42:08.939+0100 E QUERY    [thread1] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed :
connect@src/mongo/shell/mongo.js:237:13
@(connect):1:6
exception: connect failed
mongo pulp_database --eval 'db.dropDatabase();' failed! Check the output for error!
[ERROR 2019-01-08T16:42:08 verbose] mongo pulp_database --eval 'db.dropDatabase();' failed! Check the output for error!
...
[ERROR 2019-01-08T16:42:33 verbose] Jan 08 16:42:08 vm-198-147.lab.eng.pek2.redhat.com mongod.27017[11541]: [initandlisten] exception in initAndListen: 28662 Cannot start server. Detected data files in /var/lib/mongodb created by the 'wiredTiger' storage engine, but the specified storage engine was 'mmapv1'., terminating
...
  Something went wrong! Check the log for ERROR-level output
  The full log is at /var/log/foreman-installer/satellite.log
[ INFO 2019-01-08T16:54:31 verbose] All hooks in group post finished
[ INFO 2019-01-08T16:54:31 verbose] Installer finished in 804.191110789 seconds
--------------------------------------------------------------------------------
Scenario [Restore backup] failed.
...

problem is that /etc/* files are restored first (Restore configs from backup) where /etc/opt/rh/rh-mongodb34/mongod.conf contains
storage.engine: mmapv1
so later when it does sth. with mongo, it fails to start because it detects wiredtiger files in /var/lib/mongodb

Version-Release number of selected component (if applicable):
sat 6.5 snap 10
rubygem-foreman_maintain-0.3.0-1.el7sat.noarch

How reproducible:
always

Steps to Reproduce:
1. install satellite 6.3 (last version with old mongo)
2. upgrade to 6.4 
3. upgrade to 6.5
4. foreman-maintain backup ...
5. satellite-installer --upgrade-mongo-storage-engine
6. foreman-maintain restore ...