Sometimes, a developer (or security specialist) will need to capture and analyze Bluetooth HCI (Host Controller Interface) packets. Enabling this will place them in a file on the device storage (/sdcard/btsnoop_hci.log) for retrieval. You can then analyze them with a program like Wireshark.
So use a file manager, look in internal storage for btsnoop_hci.log, and delete it. (And disable the Bluetooth snoop logging.)