Clarify Jira Site Import screen - user options are per site

While testing migrations, customers want to ensure that any selections made on this screen will not affect any of their other production sites within their cloud organization, especially if SCIM is already enabled. Support confirmed that these options only apply on a per-site basis.

The ask here is to clarify directly on the import screen (or under the corresponding ? icons) that the 3 user options only apply on a per-site basis and will not affect other production sites. The public documentation has already been updated. See Step 5, 5.b: https://confluence.atlassian.com/cloud/use-jira-site-import-to-migrate-from-server-to-cloud-972349848.html