title: Android things pairing with BLE
body: <p>I have a raspi3 with android things on it and I want to connect to a BLE device that requires a user authentication for bounding.</p>
  
  <p>On a phone, after having set a characteristic on the BLE device, I am able to receive the Broadcast event </p>
  
  <pre><code>BluetoothDevice.ACTION_PAIRING_REQUEST
  </code></pre>
  
  <p>and in the meantime a dialog from android system opens asking me to accept the bluetooth connection (it has pairing variant = 3 (PAIRING_VARIANT_CONSENT)). When I accept it on the dialog everything goes nice and I connect to the device.</p>
  
  <p>In my android things device I don't receive any ACTION_PAIRING_REQUEST event and my connection drops as soon as I write the characteristic on the BLE device.
  Is there any way to have the accept process on android things?</p>