removes confusing hover over tooltips from the new files restrict access modal radio buttons Fixes: CNVS-16560

Test Plan:
- Ensure that " Better File Browsing" feature flag is enabled.
- Go to Course/x/files
- Select a file.
- Click "Restrict Access" button on the toolbar.
- Verify that no confusing hover over tooltip appears on the radio buttons.
- Ensure that screen reader reads the radio buttons correctly.

Change-Id: I3396d2a16a2d7e75e54ac495644f36b9a34a8097
Reviewed-on: https://gerrit.instructure.com/43551
Reviewed-by: Ryan Shaw <ryan@instructure.com>
Product-Review: Ryan Shaw <ryan@instructure.com>
QA-Review: Ryan Shaw <ryan@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>