CEC VTS: Add testSendRandomMessage

VTS test to send a CEC message from sendMessage() and validate that
message by capturing the cec-client console output.

Bug: 157402557
Test: vts-tradefed run commandAndExit vts-hal-tv -m
VtsHalTvCecV1_0HostCecClient

Change-Id: I98900b5b6180931edea9dcdf33115c70c902fce7
4 files changed