base

Handle the power state change.

- Add BrocastIntent listener to catch SCREEN_ON/OFF intents.
- Add callbacks onTransitionToStandBy(), onStandBy() in HdmiCecLocalDevice.java.
- When it gets the SCREEN_OFF intent, the state will be TRANSITION_TO_STANDBY,
  then when there is no outstanding actions, the state will be STANDBY.
- When the state is STANDBY, the TV device will broadcast <StandBy>.
- When it gets the SCREEN_ON intent, the state will be TRANSITION_TO_ON,
  then when the initialization is done, the state will be ON.
- When the state is ON and it receives <StandBy> CEC message, it will force
  the system to go to sleep.
- When the state is STANDBY and it receives the cec messages to wake-up the
  system, it will force the system to wake up from sleep.
- Manage the active source state for the playback device.

Change-Id: Ib473219a0b0deb5224df89386db5a83720000411