bluetooth: let device trust the DUT at pairing

When a DUT pairs a Raspberry Pi device for the first time,
we need to let the Raspberry Pi device trust the DUT.
Otherwise, it would lead to the following error:

  Authentication attempt without agent
  Access denied: org.bluez.Error.Rejected

BUG=b:147467915, b:147351296
TEST=Remove the paired devices from both the Raspberry Pi
and the DUT. And then conduct the bluetooth_AdapterAUSanity test.
It should pass.

Change-Id: I23571603c6493f7aef834f15773b705749474ad7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/chameleon/+/2094404
Commit-Queue: Shyh-In Hwang <josephsih@chromium.org>
Reviewed-by: Daniel Winkler <danielwinkler@google.com>
Tested-by: Shyh-In Hwang <josephsih@chromium.org>
1 file changed