Reduce 180Mbps in CI test for 162 PRB

Due to t-Reordering, if requesting more than 100% of resources allow,
leads to dropped packets at RLC that PDCP waits for in reordering

ci-scripts/xml_files/fr1_sa_quectel_162prb.xml

@@ -98,8 +98,8 @@
 
 	<testCase id="072000">
 		<class>Iperf</class>
-		<desc>iperf (DL/200Mbps/UDP)(60 sec)(single-ue profile)</desc>
-		<iperf_args>-u -b 200M -t 60</iperf_args>
+		<desc>iperf (DL/180Mbps/UDP)(60 sec)(single-ue profile)</desc>
+		<iperf_args>-u -b 180M -t 60</iperf_args>
 		<direction>DL</direction>
 		<id>nrmodule2_quectel</id>
 		<iperf_packetloss_threshold>50</iperf_packetloss_threshold>