Enable SafeBrowsingRealTimeUrlLookupFetchAllowlist for testing.

R=holte

Bug: 963165,966646
Change-Id: I20bbbeaa848528e7a0705dc1c22492fd0efee8aa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877665
Auto-Submit: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Steven Holte <holte@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709201}

testing/variations/fieldtrial_testing_config.json

@@ -5304,6 +5304,24 @@
             ]
         }
     ],
+    "SafeBrowsingRealTimeUrlLookupFetchAllowlist": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "SafeBrowsingRealTimeUrlLookupFetchAllowlist"
+                    ]
+                }
+            ]
+        }
+    ],
     "SafeBrowsingScoutTransitionStudy": [
         {
             "platforms": [