Add config flag to mark that local auth info was changed libWeave must upload changed local auth info to the server. BUG=25766813 Change-Id: I3d82e2dab363554b1ed7ad164edbe8fbe04a7b7a Reviewed-on: https://weave-review.googlesource.com/1801 Reviewed-by: Alex Vakulenko <avakulenko@google.com>