For #12062 - Feature Flag return to browser (#16099)

app/src/main/java/org/mozilla/fenix/FeatureFlags.kt

@@ -45,4 +45,9 @@ object FeatureFlags {
      * Enables ETP cookie purging
      */
     val etpCookiePurging = Config.channel.isNightlyOrDebug
+
+    /**
+     * Returns user to browser on cold start if they have open tabs
+     */
+    val returnToBrowserOnColdStart = Config.channel.isNightlyOrDebug
 }

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

@@ -778,7 +778,10 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
     open fun navigateToBrowserOnColdStart() {
         // Normal tabs + cold start -> Should go back to browser if we had any tabs open when we left last
         // except for PBM + Cold Start there won't be any tabs since they're evicted so we never will navigate
-        if (settings().shouldReturnToBrowser && !browsingModeManager.mode.isPrivate) {
+        if (FeatureFlags.returnToBrowserOnColdStart &&
+            settings().shouldReturnToBrowser &&
+            !browsingModeManager.mode.isPrivate
+        ) {
             openToBrowser(BrowserDirection.FromGlobal, null)
         }
     }