gold-common.json5: Clean images for goldpushk-{healthy,crashing}-server.
gold-common.json5: Clean images for goldpushk-{healthy,crashing}-server.

Bug: skia:9076
Change-Id: Ic1265147e6ca8a1b0eb7476b8127653fbc08744b
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/245373
Auto-Submit: Leandro Lovisolo <f558143c2568be8d55575d13f30a1fc5cb8009d5@google.com>
Reviewed-by: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>
Commit-Queue: Leandro Lovisolo <f558143c2568be8d55575d13f30a1fc5cb8009d5@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