fix: switch state sync problem

app/src/main/java/com/stardust/scriptdroid/App.java

@@ -1,8 +1,10 @@
 package com.stardust.scriptdroid;
 
 import android.app.Application;
+import android.preference.PreferenceManager;
 
 import com.stardust.util.CrashHandler;
+import com.stardust.util.StateObserver;
 
 /**
  * Created by Stardust on 2017/1/27.
@@ -11,14 +13,21 @@ import com.stardust.util.CrashHandler;
 public class App extends Application {
 
     private static App instance;
+    private static StateObserver stateObserver;
 
     public static App getApp() {
         return instance;
     }
 
+    public static StateObserver getStateObserver() {
+        return stateObserver;
+    }
+
+
     public void onCreate() {
         super.onCreate();
         Thread.setDefaultUncaughtExceptionHandler(new CrashHandler(ErrorReportActivity.class));
         instance = this;
+        stateObserver = new StateObserver(PreferenceManager.getDefaultSharedPreferences(this));
     }
 }