[NTP] Move CerseiFakeboxOnNtp fieldtrial to OmniboxBundledExperimentV1

Delete the CerseiFakeboxOnNtp fieldtrial and move the most likely to
launch variant to OmniboxBundledExperimentV1.

Bug: 958655
Change-Id: If9eec80b57454424344bea8930b132e6255bca91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1664971
Auto-Submit: Kristi Park <kristipark@chromium.org>
Commit-Queue: Nik Bhagat <nikunjb@chromium.org>
Reviewed-by: Nik Bhagat <nikunjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670317}

testing/variations/fieldtrial_testing_config.json

@@ -1348,62 +1348,6 @@
             ]
         }
     ],
-    "CerseiFakeboxOnNtp": [
-        {
-            "platforms": [
-                "chromeos",
-                "linux",
-                "mac",
-                "windows"
-            ],
-            "experiments": [
-                {
-                    "name": "EnabledAlt",
-                    "enable_features": [
-                        "UseAlternateFakeboxOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledAltWithIcon",
-                    "enable_features": [
-                        "FakeboxSearchIconOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledAltWithIconColor",
-                    "enable_features": [
-                        "FakeboxSearchIconColorOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledAltRect",
-                    "enable_features": [
-                        "UseAlternateFakeboxRectOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledAltRectWithIcon",
-                    "enable_features": [
-                        "FakeboxSearchIconOnNtp",
-                        "UseAlternateFakeboxRectOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledAltRectWithIconColor",
-                    "enable_features": [
-                        "FakeboxSearchIconColorOnNtp",
-                        "UseAlternateFakeboxRectOnNtp"
-                    ]
-                },
-                {
-                    "name": "EnabledShortString",
-                    "enable_features": [
-                        "FakeboxShortHintTextOnNtp"
-                    ]
-                }
-            ]
-        }
-    ],
     "CertDualVerificationTrial": [
         {
             "platforms": [
@@ -3677,7 +3621,8 @@
                         "OmniboxRichEntitySuggestions",
                         "OmniboxTailSuggestions",
                         "OmniboxUIExperimentMaxAutocompleteMatches",
-                        "QueryInOmnibox"
+                        "QueryInOmnibox",
+                        "UseAlternateFakeboxOnNtp"
                     ]
                 }
             ]