Sets the default action of this to
This action is activated when the notification is clicked on.
The action in
detailed_action must be an application-wide action (it must start with "app."). If
contains a target, the given action will be activated with that target as its parameter. See
parse_detailed_name for a description of the format for
When no default action is set, the application that the notification was sent on is activated.
a detailed action name