Refactor ConnectionManager and DeviceInfoManager

lib/managers/device_info_manager.class.dart

@@ -0,0 +1,29 @@
+part of '../main.dart';
+
+class DeviceInfoManager {
+
+  static final DeviceInfoManager _instance = DeviceInfoManager._internal();
+
+  factory DeviceInfoManager() {
+    return _instance;
+  }
+
+  String unicDeviceId;
+  String manufacturer;
+  String model;
+  String osName;
+  String osVersion;
+
+  DeviceInfoManager._internal();
+
+  loadDeviceInfo() {
+    DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
+    deviceInfo.androidInfo.then((androidInfo) {
+      unicDeviceId = "${androidInfo.model.toLowerCase().replaceAll(' ', '_')}_${androidInfo.androidId}";
+      manufacturer = "${androidInfo.manufacturer}";
+      model = "${androidInfo.model}";
+      osName = "Android";
+      osVersion = "${androidInfo.version.release}";
+    });
+  }
+}