定义环境变化信息

定义环境变化信息。Configuration是接口定义，仅做字段声明。

系统能力：以下各项对应的系统能力均为SystemCapability.Ability.AbilityBase

具体字段描述参考ohos.app.ability.Configuration.d.ts文件

示例：

import UIAbility from '@ohos.app.ability.UIAbility';

let callbackId;

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.log('MyAbility onCreate')
    globalThis.applicationContext = this.context.getApplicationContext();
    let environmentCallback = {
      onConfigurationUpdated(config){
        console.log('onConfigurationUpdated config: ${JSON.stringify(config)}');
      },
      onMemoryLevel(level){
        console.log('onMemoryLevel level: ${level}');
      }
    };
    // 1.获取applicationContext
    let applicationContext = globalThis.applicationContext;
    // 2.通过applicationContext注册监听系统环境变化
    callbackId = applicationContext.on('environment', environmentCallback);
    console.log('registerEnvironmentCallback callbackId: ${callbackId}');
  }
}