v4.27.0: OpenTracks

Changes:
- Sensor: power from Bosch eBike
- Sensors: include already bonded Bluetooth devices (like Bosch eBike)
- Barometer: enforce sampling frequency

Bugfix:
- Dashboard API: did not provide update
- GPS could not be enabled with Bluetooth disabled

Developer:
- Removed Mockito
- UI tests: less flacky