Have an admin_setting which exposes a check

Test normal

1. Navigate to /admin/settings.php?section=manageantiviruses
2. Ensure that ClamAV antivirus is disabled (eye with cross icon is shown)
3. Under "Antivirus status check" confirm it says "N/A No antivirus scanners are currently enabled"
4. Enable the ClamAV antivirus (click the eye with cross icon and it should become a normal eye icon)
5. Under "Antivirus status check" confirm it says "OK 1 antivirus scanner(s) enabled, no issues have been detected in the last 20 mins" in a green notification

Test details showing

1. Open the file admin/settings/plugin.php, around line 189 where the admin_setting_check has been added for the antivirus() check
2. Enter true as the last parameter to admin_setting_check on the line from step 1, and save the changes. I.e. you should have this: 

   $temp->add(new admin_setting_check('antivirus/checkantivirus', new \core\check\environment\antivirus(), true));

1. Navigate to /admin/settings.php?section=manageantiviruses and reload the page
2. Next to the "antivirus | checkantivirus" setting, Confirm there is text below the notification such as "This status checks whether or not there has been a recent error detected based on the threshold set in the main antivirus settings."