Add a delay state into DeviceDiscoveryAction.

ag/5288959

Delay the action for 1000 ms when the current device is not a TV.
Give devices just connected to the currect device enough time to prepare
to handle incoming cec commands during DeviceDiscoveryAction.

Note that this also means TIF will be updated with delay.

Test: local tested.
Change-Id: I7df21165dc98e1388f47a1bdfe2df6efb433d94c