Load state and commands definition by calling methods of device This allows to have dynamic state and commands expansion and calls can be places near command handlers code. BUG:24267885 Change-Id: I1777b321cface7c081258fa62eec272a8a173dc8 Reviewed-on: https://weave-review.googlesource.com/1252 Reviewed-by: Alex Vakulenko <avakulenko@google.com>