staging.service: Introduce reset_failed for systemd system.

When we start a service in systemd system, there should be an interval
between two operations. But we can run a reset-failed command before
running start command to force command of start executed.

This patch make service module run reset-failed before other systemctl
command by default. But if you do not want it, just pass reset_failed=False.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>