[RCS UCE] Create the UceController instance and the exposed interface of controllers

Define the UceController and the interface of each controllers.
The UceController is responsible for receiving the requests from RCS applications and from the ImsService.
It manages these requests and deliever them to the controller which can handle the request.

Bug: 161198092
Test: atest UceController
Change-Id: Ic287124e35bd78de88ee7097fcf39a69f20827b1