title: Get SIM serial number or a unique ID
body: <p>I am using <a href="https://stackoverflow.com/a/17499889/3770134">this</a> to detect if or not my phone is Dual Sim. It works fine there but I am unable to use <code>.getSimSerialNumber();</code> in this method. It gives me the IMEI number of both the Sim slots. In fact, whatever I use <code>.getSimSerialNumber(); .getDeviceId(); .getSubscriberId(); .getLine1Number();</code> I get IMEI only and, the issue is for all my devices; Nexus, QMobile, Samsung, Huawei; I am able to check this as the IMEI is written with the slots.</p>
  
  <p>It worked fine on Eclipse and after I installed Android Studio. I don't know what is causing the problem now. Can anyone help? Is there any other way to get a unique Sim ID?</p>
  
  <p>I need it to detect my Sim card on a Web Server.</p>