Changes:
1. Remove stuff no longer needed. Lots of the heavy lifting were there
because we were running our own jenkins cluster and had to manage all
the test logs ourselves. Now they are useless.
2. Change "-j2" to "-j4" to speed up the test a little bit. Kokoro
machines have 4 logic CPUs according to their spec.

The last up-integration from github to google3 was made at commit
e28286fa but somehow the change in
that commit is not actually in the up-integration CL and as a result
that change was reverted by the down-integration. Restoring them
should make the jenkins tests running again.