bazelPath: use Jenkins magic to execute cleanup on the slave itself
bazelPath: use Jenkins magic to execute cleanup on the slave itself

The current way of doing the work, we were cleaning-up
the Jenkins master.

Also overwrite destination when moving upstream artifact

Change-Id: I7ad30e9e53fd682f72627ed00455eda9935055f8

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration