foxgirl-settings/librewolf.cfg/user-settings/auto-play.json

{
    "name": "Autoplay",
    "subcategory": "User Settings",
    "notes": "",
    "section": [
        {
            "comments": "",
            "type": "lockPref",
            "key": "media.autoplay.default",
            "value": 2
        }
    ]
}