Refactor [v125.2] Update initial experiments JSON for Nimbus (#19901) (…

…#19903)

Co-authored-by: isabelrios <1897507+isabelrios@users.noreply.github.com>
(cherry picked from commit 56f2b27)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

firefox-ios/Client/Experiments/initial_experiments.json

@@ -498,6 +498,111 @@
       "localizations": null,
       "locales": null,
       "publishedDate": null
+    },
+    {
+      "schemaVersion": "1.12.0",
+      "slug": "ios-splash-screen-timing-test-release",
+      "id": "ios-splash-screen-timing-test-release",
+      "arguments": {},
+      "application": "org.mozilla.ios.Firefox",
+      "appName": "firefox_ios",
+      "appId": "org.mozilla.ios.Firefox",
+      "channel": "release",
+      "userFacingName": "iOS Splash Screen Timing Test Release",
+      "userFacingDescription": "Adds a splash screen prior to first-run onboarding and gauges the impact to retention.",
+      "isEnrollmentPaused": false,
+      "isRollout": false,
+      "bucketConfig": {
+        "randomizationUnit": "nimbus_id",
+        "namespace": "ios-splash-screen-release-2",
+        "start": 0,
+        "count": 10000,
+        "total": 10000
+      },
+      "featureIds": [
+        "splash-screen"
+      ],
+      "probeSets": [],
+      "outcomes": [
+        {
+          "slug": "onboarding",
+          "priority": "primary"
+        },
+        {
+          "slug": "default_browser",
+          "priority": "secondary"
+        }
+      ],
+      "branches": [
+        {
+          "slug": "control",
+          "ratio": 1,
+          "feature": {
+            "featureId": "this-is-included-for-mobile-pre-96-support",
+            "enabled": false,
+            "value": {}
+          },
+          "features": [
+            {
+              "featureId": "splash-screen",
+              "enabled": true,
+              "value": {
+                "enabled": true,
+                "maximum_duration_ms": 0
+              }
+            }
+          ]
+        },
+        {
+          "slug": "treatment-a",
+          "ratio": 1,
+          "feature": {
+            "featureId": "this-is-included-for-mobile-pre-96-support",
+            "enabled": false,
+            "value": {}
+          },
+          "features": [
+            {
+              "featureId": "splash-screen",
+              "enabled": true,
+              "value": {
+                "enabled": true,
+                "maximum_duration_ms": 1500
+              }
+            }
+          ]
+        },
+        {
+          "slug": "treatment-b",
+          "ratio": 1,
+          "feature": {
+            "featureId": "this-is-included-for-mobile-pre-96-support",
+            "enabled": false,
+            "value": {}
+          },
+          "features": [
+            {
+              "featureId": "splash-screen",
+              "enabled": true,
+              "value": {
+                "enabled": true,
+                "maximum_duration_ms": 2000
+              }
+            }
+          ]
+        }
+      ],
+      "targeting": "((is_already_enrolled) || ((isFirstRun == 'true') && (app_version|versionCompare('125.2.0') >= 0)))",
+      "startDate": "2024-04-19",
+      "enrollmentEndDate": null,
+      "endDate": null,
+      "proposedDuration": 28,
+      "proposedEnrollment": 14,
+      "referenceBranch": "control",
+      "featureValidationOptOut": false,
+      "localizations": null,
+      "locales": null,
+      "publishedDate": "2024-04-19T18:09:09.240697Z"
     }
   ]
 }