sharedPreference can't get updated value from a service of another application

Question

I have 2 different android applications (app1 and app2). In app2, I tried to get the value of the sharedPreference from a service of app1. I used the following codes: In a service of app 1 :

        sharedPreferences = getSharedPreferences(PREFERENCES, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.remove("currentKey");
        editor.putString("currentKey",target);//update sharedPrerences
        editor.apply();
        Log.i(TAG,"value is" + sharedPreferences.getString("currentKey", null) );

And in app2:

        try {
                    Context context = createPackageContext("com.example.packageName",0);
                    sharedPreferences = context.getSharedPreferences(PREFERENCES,Context.MODE_PRIVATE);
                    String current = sharedPreferences.getString("currentKey",null);
                } catch (PackageManager.NameNotFoundException e) {
                    e.printStackTrace();
                }

Two apps have the same following info in the manifest:

          android:sharedUserId="com.android.example"
          android:sharedUserLabel="@string/user_id_label"

In app2, I can get the value of sharedPreference, but the problem is that the value isn't updated when the service of app1 changes value of the sharedPreference. Have no idea! If someone have fallen in the same case, please help me! Thanks a lot!