firefox: enable tab groups for when they land in ESR with TODO

conf/firefox-forbidden-policies.js

@@ -106,5 +106,8 @@ lockPref("sidebar.revamp", true);
 lockPref("sidebar.verticalTabs", true);
 lockPref("sidebar.visibility", "always-show");
 
+// Tab groups. TODO: Are these allowed? I am on ESR, so it does nothing yet.
+lockPref("browser.tabs.groups.enabled", true);
+
 // No making configuration on the last line of the file!
 //

etc/firefox/policies/policies.json

@@ -450,6 +450,12 @@
 				"Type": "boolean",
 				"Value": false
 			},
+			"browser.tabs.groups.enabled": {
+				"Comment": "TODO: Is this allowed when it lands?",
+				"Status": "default",
+				"Type": "boolean",
+				"Value": true
+			},
 			"browser.tabs.inTitlebar": {
 				"Status": "default",
 				"Type": "number",