Fix junos_command test failure (#27627)

Add a loopback interface check instead
of device specific management interface

test/integration/targets/junos_command/tests/netconf_xml/contains.yaml

@@ -5,11 +5,11 @@
   junos_command:
     commands:
       - show version
-      - show interfaces fxp0
+      - show interfaces lo0
     format: xml
     wait_for:
       - "result[0].rpc-reply.software-information.host-name contains {{ inventory_hostname_short }}"
-      - "result[1].rpc-reply.interface-information.physical-interface.name contains fxp0"
+      - "result[1].rpc-reply.interface-information.physical-interface.name contains lo0"
     provider: "{{ netconf }}"
   register: result