Adapt to upstreamed AddonManager changes

We upstreamed our patch to prevent content from accessing navigator.AddonManager in https://bugzilla.mozilla.org/show_bug.cgi?id=1384330. We need to adjust some preferences to pick this up for Tor Browser based on ESR60, namely: privacy.resistFingerprinting.block_mozAddonManager and extensions.webextensions.restrictedDomains. For the latter, see: https://bugzilla.mozilla.org/show_bug.cgi?id=1453988.