auto_register
Description:
If true (the default), the agent will always be registered when NetworkManager is running; if NetworkManager exits and restarts, the agent will re-register itself automatically.
In particular, if this property is true at construct time, then the agent will register itself with NetworkManager during construction/initialization and initialization will only complete after registration is completed (either successfully or unsuccessfully). Since 1.24, a failure to register will no longer cause initialization of SecretAgentOld to fail.
If the property is false, the agent will not automatically register with NetworkManager, and enable or register_async must be called to register it.
Calling enable has the same effect as setting this property.