Implement skeleton of new HDMI Control Service.

HdmiCecService is a system service handling HDMI-CEC features
and command. Recently we found out that industry has more
requirements to support HDMI-CEC. Also, MHL is another
standard should be in our pocket. Basically, MHL is
a standard to support communication between mobile device
and TV or Av device. As CEC is a control standard over HDMI
cable, MHL has control channel for peer device.
There behavior is very similiar. Both have commands that
can change Tv's current input and can send/receive key
to other device to control other deivce or TV.

In order to cover both CEC and MHL, current HdmiCecService
implementation has limitation. We had several
session of discussion and decided to refactor
HdmiCecService into HdmiControlService.
For each standard it will have separate controller instance
like HdmiCecController and HdmiMhlController.

In this change I didn't touch original HdmiCecService
because some component, like cast receiver, uses HdmiCecService.
For a while we will keep HdmiCecService until HdmiControlService
accomodates all features of HdmiCecService.

Change-Id: I5485280ab803dbf071d898bfbe34be0b11ce7958