Add fieldtrial_testing_config for CSD vision model

This CL removes the fieldtrial_testing_config for the DOM-based client
side phishing detection (CSD) model, since that is now launched to
Stable. It replaces that entry with a config for the new vision-based
CSD model.

Bug: 1068613
Change-Id: I072315f45044536a9851f3db2147f5d967eadbbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2333169
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Bettina Dea <bdea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#794298}

testing/variations/fieldtrial_testing_config.json

@@ -1620,27 +1620,6 @@
             ]
         }
     ],
-    "ClientSideDetectionModel": [
-        {
-            "platforms": [
-                "chromeos",
-                "linux",
-                "mac",
-                "windows"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "params": {
-                        "ModelNum": "4"
-                    },
-                    "enable_features": [
-                        "ClientSideDetectionModel"
-                    ]
-                }
-            ]
-        }
-    ],
     "CodeCacheDeletionWithoutFilter": [
         {
             "platforms": [
@@ -7617,6 +7596,27 @@
             ]
         }
     ],
+    "VisualClientSideDetectionModel": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "params": {
+                        "ModelNum": "5"
+                    },
+                    "enable_features": [
+                        "ClientSideDetectionModel"
+                    ]
+                }
+            ]
+        }
+    ],
     "VizForWebView": [
         {
             "platforms": [