kded: don't show "connection activated" notifications on launch/login
The daemon connects to NetworkManager::ActiveConnection::stateChanged signals to show notifications, and this signal gets emitted when the daemon launches to first make its connection. As a result, every time the user logs in or the plasma-nm kded module is restarted (manually or due to a crash), a "Connection activated" notification is shown. This is annoying and redundant since the connection was made with no user action taken; the user expects background processes to work normally and does not need to be explicitly notified of it.
Plasma-nm already has some logic to suppress these notifications that would be sent within the first 10 seconds after waking up from sleep, but it does not handle the case of the same thing happening right when the daemon is launched (e.g. on login).
This commit makes it handle that use case as well, with the same approach: suppressing "activated" notifications sent within the first 10 seconds.
BUG: 399973 FIXED-IN: 5.24.2