Return a std::chrono::steady_clock::duration and switch the caller in
migration manager to also use proper C++ durations.
Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
The functionality is similar to RuntimeMBean.getUptime() that's needed
in schema pulling logic.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>