Avoid dependency to flagged constants in BtHelper

A cleaner way would be to include the aconfig flag library from
BluetoothDevice. This is a more complicated approach since this would
require an apex platform dependency which is not easy (maybe even
possible) to get for VIC anymore.

This is why a simple workaround to use the same constant values in
BtHelper should work until the flag is rolled out completely.

Test: manual device type change
Bug: 335936458
Change-Id: I6880f5522607a3995b4b3aaa0d398b9a3255812a