Revert of Change net's predictor_tab_helper to use the new content Navigation API

testing/variations/fieldtrial_testing_config_mac.json

 {
     "AutofillClassifier": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
@@ skipping 94 matching lines @@
     "PageRevisitInstrumentation": [
         {
             "group_name": "Enabled"
         }
     ],
     "PasswordBranding": [
         {
             "group_name": "SmartLockBrandingSavePromptOnly"
         }
     ],
-    "PreconnectMore": [
-        {
-            "enable_features": [
-                "PreconnectMore"
-            ],
-            "group_name": "PreconnectMoreAllFrames",
-            "params": {
-                "preconnect_subframes": "true"
-            }
-        },
-        {
-            "enable_features": [
-                "PreconnectMore"
-            ],
-            "group_name": "PreconnectMoreMainFrameOnly",
-            "params": {
-                "preconnect_subframes": "false"
-            }
-        }
-    ],
     "QUIC": [
         {
             "group_name": "Enabled"
         }
     ],
     "RefreshTokenDeviceId": [
         {
             "group_name": "Enabled"
         }
     ],
@@ skipping 142 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }