guest_agent.py: Add new command 'gunetwork-get-route'

Add a new guest agent command 'gunetwork-get-routeats' to
get route info of Guest.

Signed-off-by: Dehan Meng <demeng@redhat.com>

virttest/guest_agent.py

@@ -1047,3 +1047,14 @@ def get_cpustats(self):
         cmd = "guest-get-cpustats"
         self.check_has_command(cmd)
         return self.cmd(cmd)
+
+    def get_network_route(self):
+        """
+        Get the network route of the guest by guest agent operation
+
+        :return: a list of network route info such as 'iface' and 'gateway'
+        'metric' and 'refcnt'...
+        """
+        cmd = "guest-network-get-route"
+        self.check_has_command(cmd)
+        return self.cmd(cmd)