title: flutter_blue shows mac address instead of Names
body: <p>I am running flutter_blue example,it doesn't raise any error but after searching for bluetooth devices it shows mac address instead of Local Names.alse after clicking on connect it doesn't connect.</p>
  
  <p><img src="https://user-images.githubusercontent.com/20438582/56803463-eb332b80-6837-11e9-89f3-c00fa2a30829.jpg" alt=""></p>
  
  <p>I did make sure that other devices are ble support, even I purchased Bluetooth v4.0 usb dongle to be completely sure about Bluetooth version, but nothing changed.
  also, I thought it may be related to my android phone,I reset(factory) the phone and wiped cache but nothing changed.</p>
  
  <p>my cellphone is Sony Xperia Z3+ with android 7.1.1;</p>
  
  <p>any Idea what is wrong and why I can't get devices name in scan?</p>