Bluetooth: implement bluetooth_Sanity_Discovery

This test is another example of a Bluetooth test with a separate
tester device (stumpy with testbed-ap profile), and is the mirror of
bluetooth_Sanity_Discoverable.

BUG=chromium:256771
TEST=run_remote_tests

Change-Id: I00142fc5183af8466638ef7b1bc64cae4a6c87fb
Reviewed-on: https://chromium-review.googlesource.com/67010
Reviewed-by: Scott James Remnant <keybuk@chromium.org>
Commit-Queue: Scott James Remnant <keybuk@chromium.org>
Tested-by: Scott James Remnant <keybuk@chromium.org>
9 files changed