Add libjdwp to buildbot-build.sh common targets

We need this in order to run libjdwp tests on the chromium buildbots.

Bug: 62821960
Test: ./art/tools/buildbot-build.sh --host
Test: ./art/tools/run-libjdwp-tests.sh --mode=host --variant=x32
Change-Id: I5c55f273cbfa43494060f4ecca473ef9a39a6c78