[Terminal] Refactor out V1ViewProvider and V2ViewProvider.

These two structs are not really necessary. The `add_service` function
takes a `ServiceFactory`, but that trait is already implemented on the
2-tuple `(&str, FnMut(Channel))`. So removing those structs and passing
in such a tuple is simpler.

Testing: Manually tested that the terminal still worked as before.

Change-Id: I6aa05560fa1858c01287bfbe20b9278ea0e2e8b7
1 file changed