core: Bluetooth tracker not working in 0.98.x when running HA in Docker on NUC.

Home Assistant release with the issue:

0.98.0+

Last working Home Assistant release (if known): 0.97.x

Operating environment (Hass.io/Docker/Windows/etc.):

NUC/Docker/Home Assistant Component/platform:

https://www.home-assistant.io/components/bluetooth_tracker/

Description of problem: The 0.98.x Home Assistant Docker image cannot communicate with the NUC’s built-in bluetooth adapter.

Problem-relevant configuration.yaml entries and (fill out even if it seems unimportant):

  - platform: bluetooth_tracker
    request_rssi: true
    consider_home: 60
    new_device_defaults:
      track_new_devices: false

Traceback (if applicable):

2019-08-30 18:02:24 INFO (SyncWorker_15) [homeassistant.loader] Loaded bluetooth_tracker from homeassistant.components.bluetooth_tracker
  File "/usr/local/lib/python3.7/site-packages/bluetooth/bluez.py", line 31, in discover_devices
_bluetooth.error: (4, 'Interrupted system call')
  File "/usr/src/homeassistant/homeassistant/components/bluetooth_tracker/device_tracker.py", line 97, in setup_scanner
  File "/usr/src/homeassistant/homeassistant/components/bluetooth_tracker/device_tracker.py", line 72, in discover_devices
  File "/usr/local/lib/python3.7/site-packages/bluetooth/bluez.py", line 34, in discover_devices
    raise BluetoothError ("error communicating with local "
bluetooth.btcommon.BluetoothError: error communicating with local bluetooth adapter

Additional information: If I SSH into the NUC, I can run ‘hcitool scan’ and ‘hcitool lescan’.

Hcitool scans also work in the container, like so:

docker exec -it home-assistant sh