Revert "Enable Cert Verifier Service by Default"

This reverts commit aae065c3.

Reason for revert: Need to revert a parent change (crrev.com/c/2524812)

Original change's description:
> Enable Cert Verifier Service by Default
>
> Bug: 1015134, 1094483
> Change-Id: Ie7c2c5e1c32fa7066c56241966385e1b25fcf61f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505748
> Reviewed-by: Caitlin Fischer <caitlinfischer@google.com>
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Commit-Queue: Matthew Denton <mpdenton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#825181}

TBR=jam@chromium.org,mpdenton@chromium.org,caitlinfischer@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1015134, 1094483, 1146899
Change-Id: I5fc021f589657d471749e909b7b2449336c9db3b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2525465
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825250}

services/network/public/cpp/features.cc

@@ -167,7 +167,7 @@ const base::Feature kRequestInitiatorSiteLockEnfocement = {
 // performed in the network service, but will instead be brokered to a separate
 // cert verification service potentially running in a different process.
 const base::Feature kCertVerifierService{"CertVerifierService",
-                                         base::FEATURE_ENABLED_BY_DEFAULT};
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables preprocessing requests with the Trust Tokens API Fetch flags set,
 // and handling their responses, according to the protocol.

testing/variations/fieldtrial_testing_config.json

@@ -1354,6 +1354,24 @@
             ]
         }
     ],
+    "CertVerifierService": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "CertVerifierService"
+                    ]
+                }
+            ]
+        }
+    ],
     "CheckOfflineCapability": [
         {
             "platforms": [