Validate all messages on construction

Refactors message validation in preparation for letting messages have
their own class:
- HdmiCecMessage is now built using a static factory method, which
validates the message and stores the result in an instance variable.
- HdmiCecMessageValidator is now static to remove its dependence on
HdmiControlService and allow HdmiCecMessage construction to use it.
- To achieve this, validation steps that are dependent on a
HdmiControlService instance are now done in HdmiControlService instead.
These are really verification steps instead of validation steps, as they
depend on the state a specific CEC network - for example, they include
checks for whether a physical address has a valid port on a local TV
device.

Change-Id: I5e8c0bbeb7069e3b5cc797d6fe98470ecddda438
Bug: 207359637
Test: atest com.android.server.hdmi