[pfcwd] Fix the polling interval time granularity (#1912)

Fixes #8773
Pfcwd regressions were observed due to the changes in the PR sonic-net/sonic-sairedis#878. Hence aligning the polling interval in lua script to use microseconds

**How I verified it**
Ran pfcwd tests that were failing prior to this change and they passed

orchagent/pfc_detect_barefoot.lua

@@ -1,12 +1,12 @@
 -- KEYS - queue IDs
 -- ARGV[1] - counters db index
 -- ARGV[2] - counters table name
--- ARGV[3] - poll time interval
+-- ARGV[3] - poll time interval (milliseconds)
 -- return queue Ids that satisfy criteria
 
 local counters_db = ARGV[1]
 local counters_table_name = ARGV[2]
-local poll_time = tonumber(ARGV[3])
+local poll_time = tonumber(ARGV[3]) * 1000
 
 local rets = {}
 

orchagent/pfc_detect_broadcom.lua

@@ -1,12 +1,12 @@
 -- KEYS - queue IDs
 -- ARGV[1] - counters db index
 -- ARGV[2] - counters table name
--- ARGV[3] - poll time interval
+-- ARGV[3] - poll time interval (milliseconds)
 -- return queue Ids that satisfy criteria
 
 local counters_db = ARGV[1]
 local counters_table_name = ARGV[2]
-local poll_time = tonumber(ARGV[3])
+local poll_time = tonumber(ARGV[3]) * 1000
 
 local rets = {}
 

orchagent/pfc_detect_innovium.lua

@@ -1,12 +1,12 @@
 -- KEYS - queue IDs
 -- ARGV[1] - counters db index
 -- ARGV[2] - counters table name
--- ARGV[3] - poll time interval
+-- ARGV[3] - poll time interval (milliseconds)
 -- return queue Ids that satisfy criteria
 
 local counters_db = ARGV[1]
 local counters_table_name = ARGV[2]
-local poll_time = tonumber(ARGV[3])
+local poll_time = tonumber(ARGV[3]) * 1000
 
 local rets = {}
 

orchagent/pfc_detect_nephos.lua

@@ -1,12 +1,12 @@
 -- KEYS - queue IDs
 -- ARGV[1] - counters db index
 -- ARGV[2] - counters table name
--- ARGV[3] - poll time interval
+-- ARGV[3] - poll time interval (milliseconds)
 -- return queue Ids that satisfy criteria
 
 local counters_db = ARGV[1]
 local counters_table_name = ARGV[2]
-local poll_time = tonumber(ARGV[3])
+local poll_time = tonumber(ARGV[3]) * 1000
 
 local rets = {}