alloy: Remove optimization/prediction service usage (see issue #3352)

This service is required by the "PermissionOnDeviceNotificationPredictions"
feature which is enabled by default in https://crbug.com/1350956. It uses a
Google backend service as described at https://go.dev/solutions/google/chrome.

This change removes the usage of PredictionBasedPermissionUiSelector, which
triggered this dependency, along with related startup complexity that was added
to support the optimization/prediction service in the M106 update.

libcef/browser/request_context_impl.cc

@@ -183,6 +183,7 @@ CefRequestContextImpl::CreateGlobalRequestContext(
   config.is_global = true;
   config.settings = settings;
   CefRefPtr<CefRequestContextImpl> impl = new CefRequestContextImpl(config);
+  impl->Initialize();
   return impl;
 }
 
@@ -201,11 +202,6 @@ CefRequestContextImpl::GetOrCreateForRequestContext(
   return CefRequestContextImpl::GetOrCreateRequestContext(config);
 }
 
-void CefRequestContextImpl::InitializeGlobalContext() {
-  DCHECK(IsGlobal());
-  Initialize();
-}
-
 bool CefRequestContextImpl::VerifyBrowserContext() const {
   if (!CEF_CURRENTLY_ON_UIT()) {
     NOTREACHED() << "called on invalid thread";