Xray Health Check creates new custom fields for the Begin Date, End Date, and Revision each time the re-install button is clicked

Description

Xray Health Check creates new custom fields for the Begin Date, End Date, and Revision each time the re-install button is clicked. This issue occurs on new Jira Cloud instances that do not have any projects. 

Pre-conditions

• Create a new Jira Cloud instance without any projects
• Install Xray 

How to reproduce:

1-Create a new Jira Cloud instance without any projects.
2- Install Xray.
3- Access the Xray Health Check; it will display that some Xray fields are not installed.

4- Click on the "Re-install" button. The system will display that some custom fields are missing, which is expected since these fields are only created when a new project is added, or migration is performed.

5- Click on the re-install button a couple of times. 

Actual result/Attachments

The Xray creates one custom field for each one of them every time you click on the re-install button. 

Expected result

Xray should not create duplicate custom fields when clicking the "Re-install" button multiple times.