test: Wait for dialog to close in TestAutoUpdates.testBasic
test: Wait for dialog to close in TestAutoUpdates.testBasic

Saving the settings takes a while, let's make sure the dialog behaves
properly. Introduce a little helper to avoid repetition.

martinpitt/cockpit,cockpit-project/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit,cockpit-project/cockpit,martinpitt/cockpit,cockpit-project/cockpit,martinpitt/cockpit,mvollmer/cockpit,mvollmer/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit