Set a permanent directory for the container logs

Set a permanent directory for the container logs

- Currently the container logs (cps-and-ncmp) being stored in the cps
  repository (in k6-tests/logs directory). In every build, cps code base
  being fetched freshly. Thus, the zipped container logs being lost.
- Now, by using the WORKSPACE variable set by Jenkins job, the logs will
  be stored under the root directory of WORKSPACE permanently.

Issue-ID: CPS-2676

Change-Id: I0f7f9a46b94fc3e438de39bbab04f9a59daf446b
Signed-off-by: halil.cakal <halil.cakal@est.tech>