[6.15.z] Fix Upgrade scenarios

[Satellite-QE]

Cherrypick of PR: #16477

Problem Statement

Provisioning Template and Foreman Discovery Upgrade Scenario tests are failing with JSON parse error.

Solution

• Updated test_pre_scenario_provisioning_templates to save hostname instead of host id in pre_upgrade_data file.
• Saving FDI version in string format in test_pre_upgrade_fdi_version as Version type data is not supported to be stored.

Related Issues

[Satellite-QE]

trigger: test-robottelo
pytest: tests/upgrades/test_discovery.py -k test_pre_upgrade_fdi_version -m pre_upgrade

[Satellite-QE]

PRT Result

Build Number: 9077
Build Status: UNSTABLE
PRT Comment: pytest tests/upgrades/test_discovery.py -k test_pre_upgrade_fdi_version -m pre_upgrade --external-logging
Test Result : ====== 1 passed, 1 deselected, 10 warnings, 1 error in 974.07s (0:16:14) =======

[Satellite-QE]

PRT Result

Build Number: 9087
Build Status: SUCCESS
PRT Comment: pytest tests/upgrades/test_discovery.py -k test_pre_upgrade_fdi_version -m pre_upgrade --external-logging
Test Result : =========== 1 passed, 1 deselected, 10 warnings in 825.00s (0:13:44) ===========