Continue running background apps when Brave is closed

Setting the policy to Enabled turns background mode on. In background mode, a Brave process is started on OS sign-in and keeps running when the last browser window is closed, allowing background apps and the browsing session to remain active. The background process displays an icon in the system tray and can always be closed from there. Setting the policy to Disabled turns background mode off. If you set the policy, users can't change it in the browser settings. If unset, background mode is off at first, but users can change it.