This test cannot run on boards that have a native USB REPL, so rename it to
indicate that its "special". This makes it easier to run a subset of
tests, for example:
./run-multitests.py multi_bluetooth/ble*.py
./run-multitests.py multi_bluetooth/perf*.py
./run-multitests.py multi_bluetooth/stress*.py
Signed-off-by: Damien George <damien@micropython.org>