Fix problem where HTTPSE toggle doesn't work (always upgrades)

Fixes brave/brave-browser#9099
Unfixes brave/brave-browser#4381

--------

Revert "Merge pull request #4537 from jonathanKingston/bug-4381"

This reverts commit 86bf5ed, reversing
changes made to affeac4.

app/brave_main_delegate.cc

@@ -30,13 +30,11 @@
 #include "components/offline_pages/core/offline_page_feature.h"
 #include "components/omnibox/common/omnibox_features.h"
 #include "components/password_manager/core/common/password_manager_features.h"
-#include "components/security_state/core/features.h"
 #include "components/sync/driver/sync_driver_switches.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "services/network/public/cpp/features.h"
-#include "third_party/blink/public/common/features.h"
 #include "third_party/widevine/cdm/buildflags.h"
 #include "ui/base/ui_base_features.h"
 
@@ -155,13 +153,7 @@ bool BraveMainDelegate::BasicStartupComplete(int* exit_code) {
 
   // Enabled features.
   const std::unordered_set<const char*> enabled_features = {
-    // Upgrade all mixed content
-      blink::features::kMixedContentAutoupgrade.name,
       password_manager::features::kPasswordImport.name,
-    // Remove URL bar mixed control and allow site specific override instead
-      features::kMixedContentSiteSetting.name,
-    // Warn about Mixed Content optionally blockable content
-      security_state::features::kPassiveMixedContentWarning.name,
     // Enable webui dark theme: @media (prefers-color-scheme: dark) is gated on
     // this feature.
       features::kWebUIDarkMode.name,