sandbox: Track and store the pod resolv.conf path

When we get a pod with DNS settings, we need to build
a resolv.conf file and mount it in all pod containers.
In order to do that, we have to track the built resolv.conf
file and store/load it.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

server/sandbox.go

@@ -140,6 +140,7 @@ type sandbox struct {
 	shmPath        string
 	cgroupParent   string
 	privileged     bool
+	resolvPath     string
 }
 
 const (