Wipe PID and ConmonPID in state after container stops

Matches the behavior of Docker.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

libpod/container_internal.go

@@ -1044,6 +1044,8 @@ func (c *Container) stop(timeout uint) error {
 		return err
 	}
 
+	c.state.PID = 0
+	c.state.ConmonPID = 0
 	c.state.StoppedByUser = true
 	if err := c.save(); err != nil {
 		return errors.Wrapf(err, "error saving container %s state after stopping", c.ID())

libpod/oci.go

@@ -234,6 +234,8 @@ func (r *OCIRuntime) updateContainerStatus(ctr *Container, useRuntime bool) erro
 
 		// Alright, it exists. Transition to Stopped state.
 		ctr.state.State = define.ContainerStateStopped
+		ctr.state.PID = 0
+		ctr.state.ConmonPID = 0
 
 		// Read the exit file to get our stopped time and exit code.
 		return ctr.handleExitFile(exitFile, info)