Install the HDMI CEC and HDMI connection APEX packages plus the
android.hardware.hdmi.cec.xml feature file, set the playback-device
CEC properties, and give system ownership of /dev/cec0 in ueventd.
The connection HAL now reports a single HDMI output port and monitors
/sys/class/drm/card0-HDMI-A-1/status with poll(), reporting hotplug
transitions through the AIDL callback and shutting the monitor thread
down through an eventfd.
The CEC HAL now polls POLLPRI for CEC_DQEVENT and POLLIN for
CEC_RECEIVE, guards the ioctl paths against an uninitialised adapter,
and bounds message length by CEC_MAX_MSG_SIZE.
