A lof of devices will simply work anyway even if already paired in
Android bluetooth settings. Discover them by default, but warn the user
if the device is not known to pair correctly if already paired in Android
settings. Allows this warning to be disabled to known working devices.
The refactored DiscoveryActivityV2 does not freeze anymore, even under
maximum scanning intensity on older phones, and seems to not have
introduced any regressions.