This fix tries to cover the issue raised in #22463 by emitting
events for docker daemon so that user could be notified by
scenarios like config reload, etc.
This fix adds the `daemon reload`, and events for docker daemon.
Additional tests have been added to cover the changes in this fix.
This fix fixes#22463.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Upstream-commit: 91466baa3f
Component: cli
93a4d96e98