[6.13.z] Modify ansible variable test to cover non-admin scenario

[Satellite-QE]

Cherrypick of PR: #15416

Problem Statement

Currently, ansible variable test covers only admin scenario, and as part of component audit its suggest to modify this test to cover non-admin user scenario as well, and delete the duplicate test which test create delete

Solution

• Parametrizing the existing test to cover both admin and non-admin user scenarios with few more fixes
• Deleting the test test_positive_create_and_delete_variable which tests create delete which is covered already in other test.

[Satellite-QE]

trigger: test-robottelo
pytest: tests/foreman/ui/test_ansible.py::TestAnsibleCfgMgmt::test_positive_create_delete_variable_with_overrides

[Satellite-QE]

PRT Result

Build Number: 7410
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/ui/test_ansible.py::TestAnsibleCfgMgmt::test_positive_create_delete_variable_with_overrides --external-logging
Test Result : ================= 2 passed, 36 warnings in 1153.97s (0:19:13) ==================