Add UpdaterRuntime class

This class adds a wrapper to the runtime dependent functions. Therefore,
the behavior of update on device stays the same, while simulators can
have their own implementations. Also change the caller side of the
registered updater functions to call these runtime wrappers.

Bug: 131911365
Test: unit tests pass, sideload an update on cuttlefish
Change-Id: Ib3ab67132991d67fc132f27120e4152439d16ac5