优化代码

app/src/main/java/com/electric/chargingpile/activity/FindActivity.java

    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(networkChangeReceiver);
        handler.removeCallbacksAndMessages(null);
        handler = null;
    }
    public static void showInstalledAppDetails(Context context, String packageName) {