The parameters that iperf3 testcase support now maybe insufficient in some usecase.
The test case should support parameters such as: windows size and length of buffer.
This work is about adding more parameters in testcase yaml file
Change-Id: I8c900a4a8909d97543cf837a02c76a6aee19f439 Signed-off-by: Ace Lee <liyin11@huawei.com>