实现
构造函数
new SystemInfo()
new SystemInfo(): SystemInfo返回值
SystemInfo方法
getOperatingSystemInfo()
getOperatingSystemInfo(): IOperatingSystemInfo返回值
IOperatingSystemInfogetUptime()
getUptime():Promise<MonotonicDuration>
返回值
Promise<MonotonicDuration>
isEmulator()
isEmulator():Promise<boolean>
返回值
Promise<boolean>

