Add field trial config for AutofillPreviewStyleExperiment

Bug: 874094
Change-Id: Id80332c84f574b70ba0b0e50f54aebb681276082
Reviewed-on: https://chromium-review.googlesource.com/1251229Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Fabio Tirelo <ftirelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595179}

testing/variations/fieldtrial_testing_config.json

@@ -623,6 +623,33 @@
             ]
         }
     ],
+    "AutofillPreviewStyleExperiment": [
+        {
+            "platforms": [],
+            "experiments": [
+                {
+                    "name": "Enabled_BlackOnGoogleBlue050_V2",
+                    "params": {
+                        "bg_color": "#E8F0FE",
+                        "color": "#000000"
+                    },
+                    "enable_features": [
+                        "AutofillPreviewStyleExperiment"
+                    ]
+                },
+                {
+                    "name": "Enabled_BlackOnGoogleYellow050_V2",
+                    "params": {
+                        "bg_color": "#E6F4EA",
+                        "color": "#000000"
+                    },
+                    "enable_features": [
+                        "AutofillPreviewStyleExperiment"
+                    ]
+                }
+            ]
+        }
+    ],
     "AutofillResetFullServerCardsOnAuthError": [
         {
             "platforms": [