chore: update show queue counters api to use -n (#15944)

Description of PR
Previously we're using sudo ip netns exec asic0 show queue counter for showing the queue counter in multi-asic. However with the new apis, -n is supported natively in show queue counter -n asic0

This PR updates so that in get_egress_queue_count will use the new queue counters.

The queue counter support was added in the original PR:

suppport multi asic for show queue counter sonic-utilities#2439
Cherry-pick to 202205:

Double commit #2439 suppport multi asic for show queue counter sonic-utilities#2647
Summary:
Fixes # (issue) #15856

Approach
What is the motivation for this PR?
How did you do it?
Adjust the command to use the new format show queue counter -n asic0

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

tests/common/snappi_tests/common_helpers.py

@@ -990,8 +990,8 @@ def get_egress_queue_count(duthost, port, priority):
     # If DUT is multi-asic, asic will be used.
     if duthost.is_multi_asic:
         asic = duthost.get_port_asic_instance(port).get_asic_namespace()
-        raw_out = duthost.shell("sudo ip netns exec {} show queue counters {} | sed -n '/UC{}/p'".
-                                format(asic, port, priority))['stdout']
+        raw_out = duthost.shell("show queue counters {} -n {} | sed -n '/UC{}/p'".
+                                format(port, asic, priority))['stdout']
         total_pkts = "0" if raw_out.split()[2] == "N/A" else raw_out.split()[2]
         total_bytes = "0" if raw_out.split()[3] == "N/A" else raw_out.split()[3]
     else: