fix: fix port does not exist error test_bgp_queue (#15949)

Description of PR
Summary:
Fixes # (issue) 30457143

Currently this is using the old method of capturing queue counters:

sudo ip netns exec asic1 show queue counters Ethernet128
This will throw an issue with some testbed and says Ethernet128 does not exists. (haven't had chance to confirm why)

However since we have new support for -n sonic-net/sonic-utilities#2439 we should be using this instead

Tested by running manual commands

admin@str3-8800-lc4-1:~$ sudo ip netns exec asic1 show queue counters Ethernet128
Port doesn't exist! Ethernet128
admin@str3-8800-lc4-1:~$ show queue counters Ethernet128 -n asic1
For namespace asic1:
       Port    TxQ    Counter/pkts    Counter/bytes    Drop/pkts    Drop/bytes
-----------  -----  --------------  ---------------  -----------  ------------
Ethernet128    UC0               0                0            0             0
...
Type of change

Approach
What is the motivation for this PR?
How did you do it?
Update the test to use new APIs that support -n

How did you verify/test it?
Manually run, needs to verify with available testbed.

Signed-off-by: Austin Pham <[email protected]>

tests/bgp/test_bgp_queue.py

@@ -19,7 +19,8 @@ def get_queue_counters(asichost, port, queue):
     Return the counter for a given queue in given port
     """
     cmd = "show queue counters {}".format(port)
-    output = asichost.command(cmd)['stdout_lines']
+    output = asichost.command(cmd, new_format=True)['stdout_lines']
+
     txq = "UC{}".format(queue)
     for line in output:
         fields = line.split()

tests/common/devices/sonic_asic.py

@@ -407,10 +407,12 @@ def create_ssh_tunnel_sai_rpc(self):
              " -L *:{}:{}:{} localhost").format(self.get_rpc_port_ssh_tunnel(), ns_docker_if_ipv4,
                                                 self._RPC_PORT_FOR_SSH_TUNNEL))
 
-    def command(self, cmdstr):
+    def command(self, cmdstr, new_format=False):
         """
             Prepend 'ip netns' option for commands meant for this ASIC
 
+            If new format is provided (new_format=True) we use the syntax "{cmd} -n asic{index}" instead.
+
             Args:
                 cmdstr
             Returns:
@@ -419,7 +421,10 @@ def command(self, cmdstr):
         if not self.sonichost.is_multi_asic or self.namespace == DEFAULT_NAMESPACE:
             return self.sonichost.command(cmdstr)
 
-        cmdstr = "sudo ip netns exec {} {}".format(self.namespace, cmdstr)
+        if new_format:
+            cmdstr = "sudo {} {}".format(cmdstr, self.cli_ns_option)
+        else:
+            cmdstr = "sudo ip netns exec {} {}".format(self.namespace, cmdstr)
 
         return self.sonichost.command(cmdstr)