Issue #24733: Setup search for Unified Search experimentation

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -1290,9 +1290,9 @@ class Settings(private val appContext: Context) : PreferencesHolder {
     /**
      * Indicates if the Unified Search feature should be visible.
      */
-    var showUnifiedSearchFeature by featureFlagPreference(
+    var showUnifiedSearchFeature by lazyFeatureFlagPreference(
         key = appContext.getPreferenceKey(R.string.pref_key_show_unified_search),
-        default = false,
+        default = { homescreenSections[HomeScreenSection.UNIFIED_SEARCH] == true },
         featureFlag = FeatureFlags.unifiedSearchFeature
     )
 

nimbus.fml.yaml

@@ -20,6 +20,7 @@ features:
             "recent-explorations": true,
             "pocket": true,
             "contile-top-sites": false,
+            "unified-search": false,
           }
     defaults:
       - channel: nightly
@@ -31,6 +32,7 @@ features:
             "recent-explorations": true,
             "pocket": true,
             "contile-top-sites": false,
+            "unified-search": false,
           }
         }
   nimbus-validation:
@@ -310,6 +312,8 @@ types:
           description: The pocket section. This should only be available in the US.
         contile-top-sites:
           description: The sponsored shortcuts in the homescreen.
+        unified-search:
+          description: The unified search toolbar.
     MessageSurfaceId:
       description: The identity of a message surface, used in the default browser experiments
       variants: