The README that corresponds to this release is:
https://github.com/mozilla/policy-templates/blob/3c0d7fcf4ce4aaa7be5f5a3d66fa7c3e2b8487ad/README.md
This release adds the following preferences to the Preferences policy.
browser.newtabpage.activity-stream.default.sites
extensions.htmlaboutaddons.recommendations.enabled
media.peerconnection.enabled
media.peerconnection.ice.obfuscate_host_addresses.whitelist
security.osclientcerts.autoload
security.tls.hello_downgrade_check
widget.content.gtk-theme-override