mobly_driver: Pull btpeer info from test request

Add support for pulling btpeer info from test requests and make params
optional.

BUG=b:394685986
TEST=unittests

Change-Id: I21cbcfbece6432dfea1bfd9d9cbd2666d3e0ff12
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/6254248
Tested-by: Jason Stanko <jstanko@google.com>
Commit-Queue: Jason Stanko <jstanko@google.com>
Reviewed-by: Derek Beckett <dbeckett@chromium.org>
Reviewed-by: Billy Zhao <billyzhao@chromium.org>
2 files changed