Update compute_engine_scripts/buildbot/README
Update compute_engine_scripts/buildbot/README

Also uploaded the right files in drive.

BUG=skia:

Review-Url: https://codereview.chromium.org/2118813002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot