title: BluetoothPairingStateProvider: getUuids() returns null for device
body: <p><strong>Context:</strong></p>
  
  <p>I am working on a FIDO-U2F bluetooth authenticator with a nRF52 BLE SoC. and want it to test with <a href="https://github.com/googlesamples/android-fido" rel="nofollow noreferrer">google example</a>.</p>
  
  <p>So far I have implemented the <a href="https://fidoalliance.org/specs/fido-u2f-v1.2-ps-20170411/fido-u2f-bt-protocol-v1.2-ps-20170411.html" rel="nofollow noreferrer">FIDO Bluetooth specification</a> and I have a device that advertises as a FIDO-compatible device.</p>
  
  <p>Thanks to <a href="https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop" rel="nofollow noreferrer">nRF Connect</a> I have ensured that all the services and characteristics are correctly exposed and that I can interact with it only when my device is securely paired (with LTK):
  <a href="https://i.stack.imgur.com/wsIAv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wsIAv.png" alt="nRF Connect screenshot"></a></p>
  
  <p><strong>Problem:</strong></p>
  
  <p>When the app scans for eligible FIDO device, it does not find mine.</p>
  
  <p>I am stuck on the screen that ask to press a button for 5s, which I don't need to since my device responds to pairing request without user interaction and is already paired with my SAMSUNG A8.</p>
  
  <pre><code>I/BluetoothDevicePreference: onDeviceAttributesChanged :: Device = (N) D8BE86, isBonded = 12 , mIsOnProgressAddVI = false
  I/Fido: [BleScanner] startScan()
  E/Fido: [BluetoothPairingStateProvider] getUuids() returns null for device: D8:BE:86:4A:E5:65
  I/Fido: [PreferredTransportProvider] BLE enabled but no device is paired
  I/Fido: [AuthenticateBaseChimeraActivity] User selected transport ble
  I/Fido: [ViewController] Accepting proposed view {"viewName":"ble_instructions","anyU2fDevicesPaired":false}: outranks current (2 &gt; 0)
  I/Fido: [ViewPresenter] viewSelected(...) ble_instructions
  I/Fido: [U2fRequestController] onResultReceived(null, ErrorResponseData{errorCode=5})
  I/Fido: [BleScanner] stopScan()
  </code></pre>
  
  <p>I tried to remove pairing data and all I have is:</p>
  
  <pre><code>I/BluetoothDevicePreference: onDeviceAttributesChanged :: Device = (N) D8BE86, isBonded = 10 , mIsOnProgressAddVI = false
  </code></pre>
  
  <p>The advertising flags are currently set to "<em>BR/EDR not supported</em>", but I also tried "<em>LE Limited Discoverable Mode</em>" and "<em>LE General Discoverable Mode</em>" without success.</p>
  
  <p>I looked into <em>android-fido</em> sources but the BLE scan seems imported from elsewhere, I cannot debug it in this project.</p>
  
  <p>Any pointer is welcome</p>