mozilla.cfg/config/distribution/policies.json

{
  "policies": {
    
    "AppAutoUpdate": false,

    "CaptivePortal": false,

    "DisableAppUpdate": false,

    "DisableDefaultBrowserAgent": true,

    "DisableFirefoxAccounts": true,

    "DisableFirefoxStudies": true,

    "DisablePocket": true,

    "DisableProfileImport": true,

    "DisableTelemetry": true,

    "DontCheckDefaultBrowser": true,

    "OfferToSaveLogins": false,

    "OfferToSaveLoginsDefault": false,

    "SearchSuggestEnabled": false,

    "FirefoxHome": {
      "SponsoredTopSites": false,
      "Pocket": false,
      "SponsoredPocket": false,
      "Snippets": false,
      "Locked": true
    },

    "FirefoxSuggest": {
      "WebSuggestions": false,
      "SponsoredSuggestions": false,
      "ImproveSuggest": false,
      "Locked": true
    },

    "SearchEngines": {
      "PreventInstalls": false,
      "Remove": [
        "Google",
        "Bing",
        "Amazon.com"
      ]
    }
  }
}