Use tio to interact with Nexus MCU nexus_mcu.py fails when pexpect_serial is not installed in the venv. This can result in a nexus board that needs a hard reset. Use the tio command to send commands and print out serial messages. Bypass-Presubmit-Reason: tested manually Change-Id: I04e4173f50ae0f3ed07174d2d9b511a66517e351