2019-05-20T03:07:08,606 | INFO | qtp172107092-59 | metrics | 429 - appc-common-bundle - 1.5.1.SNAPSHOT | Parameters passed to SLI: [ org.onap.appc.configURL = http://admin:Kp8bJ4SXszM0WXlhak3eHlcse2gAw84vaoGGmJvUy2U@appc:8282/restconf/config/network-topology:network-topology/topology/topology-netconf/node/70a51e42-1355-4753-9288-2f782003ee8a/yang-ext:mount/sample-plugin:sample-plugin/pg-streams/, org.onap.appc.reqid = cb7fc274-0825-467d-a092-d274454c1d7c, org.onap.appc.action = modifyConfig, org.onap.appc.configJson = {"streams": {"active-streams": 6}} ]

"sample-plugin:pg-streams" instead of "stream-count:stream-count"

PUT example (POST would be differnt)
/restconf/config/network-topology:network-topology/topology/topology-netconf/node/70a51e42-1355-4753-9288-2f782003ee8a/yang-ext:mount/stream-count:stream-count/streams

{
"streams":

}