Save device secret

Device secret is needed for verification of auth tokens after device
restart.

BUG: 24110921
Change-Id: If956886fcd6325dd4b419b7ca39ccb6bc4708230
Reviewed-on: https://weave-review.googlesource.com/1180
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
11 files changed
tree: 6f595a2dee6c5ec5010b0c8d70003a13f3e677d7
  1. libweave/