Add network3g_att suite.

The network3g_att suite is used to run automated cellular tests on
devices using AT&T as the carrier.

BUG=None
TEST=`suite_utils/run_suite.py --board=expresso --suite_name=network3g_att --pool=cellular --build=<trybot build>`

Change-Id: I3347e88331f44b2ff299e6e2e743aa7b0d746541
Reviewed-on: https://chromium-review.googlesource.com/196381
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
2 files changed