ExitType defaults to `main`, which means systemd will kill all processes
in the application cgroup when the "main" process exited.
This default behavior make applications like vscode which will always
daemonlize itself killed immediately by systemd, so we should set this
property to `cgroup` instead.
refer to https://www.freedesktop.org/software/systemd/man/systemd.service.html#ExitType=
Signed-off-by: black-desk <me@black-desk.cn>
