Description of problem:
Upon running the installer to add a new destination for pulp exports an additional step of setting the pulpcore_export_destination Setting via hammer or the WebUI must be set in order to use the new export path.
This request is to update this setting value to the new value upon a successful completion of running the installer with this option.

Version-Release number of selected component (if applicable):

How reproducible:
Every time

Steps to Reproduce:
1. Run the installer with the '--foreman-proxy-content-pulpcore-additional-export-paths' option to specify a new export location.
2. Try to export and watch it export to the previously set location
3. Update the setting 'pulpcore_export_destination' to the new location and export again.
4. Export will export to the new location

Actual results:
Pulp will export to the previously set location listed in the Satellite settings

Expected results:
Use 1 action to change the export location to simplify workflow

Additional info:
This RFE comes from bugs previously filed:
https://bugzilla.redhat.com/show_bug.cgi?id=2208013
https://bugzilla.redhat.com/show_bug.cgi?id=2158186
https://access.redhat.com/solutions/7013903