Control HTTPS upgrade behavior

This policy determines how Brave handles HTTP to HTTPS upgrades to improve connection security. If this policy is set to 1 (Disabled), HTTP connections are allowed. If this policy is set to 2 (Strict), HTTPS connections are required. Users get an interstitial if HTTPS upgrade not possible. If this policy is set to 3 (Standard), HTTP is upgraded to HTTPS when available. If left unset, users can configure the HTTPS upgrade behavior in Brave Shields settings (Standard by default).