跨包调用默认配置

try {
            Context con = createPackageContext("com.android.systemui", 0);
            int id = con.getResources().getIdentifier("config_show4GForLTE",
                    "bool", "com.android.systemui");
            mShow4GForLTE = con.getResources().getBoolean(id);
        } catch (NameNotFoundException e) {
            loge("NameNotFoundException for show4GFotLTE");
            mShow4GForLTE = false;
        }