Fix specs on branches where we eliminate the last_changed_on key
Fix specs on branches where we eliminate the last_changed_on key

attributes are keyed by String objects, so this *actually* fixes it.

ManageIQ/miq_bot,imtayadeway/miq_bot,imtayadeway/miq_bot,ManageIQ/miq_bot,ManageIQ/miq_bot,imtayadeway/miq_bot,ManageIQ/miq_bot,skateman/miq_bot,skateman/miq_bot,skateman/miq_bot