[autotest] Add btsocket to external packages

This is downloaded from git and built using setup.py

BUG=chromium:348704
TEST=./utils/build_externals.py; python -c 'import common,btsocket'
CQ-DEPEND=CL:188561
DEPLOY=build_externals

Change-Id: Ice00e49e5b64b90bc85e33b1b9d06b6de4d7925e
Reviewed-on: https://chromium-review.googlesource.com/188552
Reviewed-by: Scott James Remnant <keybuk@chromium.org>
Tested-by: Scott James Remnant <keybuk@chromium.org>
Commit-Queue: Scott James Remnant <keybuk@chromium.org>
1 file changed