Bug 1501286 - Part 5: Remove the browser.contentblocking.ui.enabled pref r=johannh

Depends on D9522

Differential Revision: https://phabricator.services.mozilla.com/D9523

--HG--
extra : moz-landing-system : lando

modules/libpref/init/StaticPrefList.h

@@ -1636,13 +1636,6 @@ VARCACHE_PREF(
   bool, true
 )
 
-// Whether Content Blocking UI has been enabled.
-VARCACHE_PREF(
-  "browser.contentblocking.ui.enabled",
-   browser_contentblocking_ui_enabled,
-  bool, true
-)
-
 // Whether Content Blocking Third-Party Cookies UI has been enabled.
 VARCACHE_PREF(
   "browser.contentblocking.allowlist.storage.enabled",