Change ownership of AuthManager as it's needed by DeviceRegistrationInfo

BUG=25766813

Change-Id: I832e0ee9e440ecc4a754dd6d4dacd3c171fbab21
Reviewed-on: https://weave-review.googlesource.com/1825
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
9 files changed