Bug 1883911 - remove pref and Nimbus code for switching devices help menu item r=mconley

Differential Revision: https://phabricator.services.mozilla.com/D203764

Author: hannajones

browser/app/profile/firefox.js

@@ -2322,8 +2322,6 @@ pref("browser.migrate.interactions.passwords", false);
 
 pref("browser.migrate.preferences-entrypoint.enabled", true);
 
-pref("browser.device-migration.help-menu.hidden", false);
-
 pref("extensions.pocket.api", "api.getpocket.com");
 pref("extensions.pocket.bffApi", "firefox-api-proxy.cdn.mozilla.net");
 pref("extensions.pocket.bffRecentSaves", true);

browser/base/content/utilityOverlay.js

@@ -549,11 +549,6 @@ function buildHelpMenu() {
   if (typeof gSafeBrowsing != "undefined") {
     gSafeBrowsing.setReportPhishingMenu();
   }
-
-  if (NimbusFeatures.deviceMigration.getVariable("helpMenuHidden")) {
-    let helpMenuItem = document.getElementById("helpSwitchDevice");
-    helpMenuItem.hidden = true;
-  }
 }
 
 function isElementVisible(aElement) {

toolkit/components/nimbus/FeatureManifest.yaml

@@ -2185,17 +2185,6 @@ httpSpeculativeParallelLimit:
         branch: default
         pref: "network.http.speculative-parallel-limit"
 
-deviceMigration:
-  description: Prefs to control aspects of the new device migration experiment
-  owner: hjones@mozilla.com
-  hasExposure: false
-  isEarlyStartup: true
-  variables:
-    helpMenuHidden:
-      description: True if new help menu item should be hidden
-      type: boolean
-      fallbackPref: browser.device-migration.help-menu.hidden
-
 shopping2023:
   description: Prefs to control the 2023 shopping experiment.
   owner: jhirsch@mozilla.com