BUG-2485: This is to fix unit test failure for auto-release.

It mainly clone the change https://git.opendaylight.org/gerrit/#/c/13214/3 from master branch to stable/helium.

Change-Id: I34d23a0c1b0afdc51d1f2d141b52d99e9581690e
Signed-off-by: George Zhao <george.y.zhao@huawei.com>
Merge "BUG-2485: This is to fix unit test failure for auto-release." into stable/helium