chromeos-dbus-bindings: Leave method interface unadorned Do not prefix the adaptor method interface with a class name. Since it is wrapped in the adaptor, it is unambiguous to just call it MethodInterface. BUG=None TEST=Unit test, rebuild platform2 Change-Id: Idaaab1291fbbb1d153050f8f82ff087633fcc12f Reviewed-on: https://chromium-review.googlesource.com/221232 Reviewed-by: Paul Stewart <[email protected]> Tested-by: Paul Stewart <[email protected]> Commit-Queue: Paul Stewart <[email protected]>