[skolo] Let Macs find the mounted volumes by default.
[skolo] Let Macs find the mounted volumes by default.

Change-Id: Ia2bf1a17c7f7fc0303aebfcafead17ace066746e
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/598786
Commit-Queue: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Auto-Submit: Erik Rose <042ad22d8352d59a3d816dac710aebe65456f16e@google.com>
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>

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