[1LP][RFR] fix custom button wait for ansible issue

[digitronik]

Purpose or Intent

Test was failing as it was trying to create ansible cred before enabling ansible.

PRT Run

{{pytest: cfme/tests/automate/custom_button/test_infra_objects_ansible.py -k test_custom_button_ansible_automate_infra_obj[Clusters-virtualcenter-Localhost] -sqvv }}