Removes initial and default session

app/src/main/java/org/mozilla/fenix/components/Core.kt

@@ -56,21 +56,7 @@ class Core(private val context: Context) {
      * case all sessions/tabs are closed.
      */
     val sessionManager by lazy {
-        val sessionStorage = SessionStorage(context, engine)
-
-        SessionManager(engine, defaultSession = { Session("about:blank") }).apply {
-            sessionStorage.restore()?.let { snapshot -> restore(snapshot) }
-
-            if (size == 0) {
-                val initialSession = Session("https://www.mozilla.org")
-                add(initialSession)
-            }
-
-            sessionStorage.autoSave(this)
-                .periodicallyInForeground(interval = 30, unit = TimeUnit.SECONDS)
-                .whenGoingToBackground()
-                .whenSessionsChange()
-        }
+        SessionManager(engine)
     }
 
     /**