process_flex_bluetooth_overrides is an executable that runs before Floss starts (see the Upstart job configuration file at init/flex-bluetooth.conf) and applies overrides for Floss on Flex. It looks at the Bluetooth adapters on the system and writes the overrides found (for the Bluetooth adapter) to the file /var/lib/bluetooth/sysprops.conf.d/floss_reven_overrides.conf, which is read by Floss.