[goldpushk] goldpushk_test.go: Rename tests as <behavior>_<input>_<expected output>.
[goldpushk] goldpushk_test.go: Rename tests as <behavior>_<input>_<expected output>.

This adopts the same convention as we've started using elsewhere in Gold.

Change-Id: I5c6abe974cbf4f78f5362ec93daf001f18038160
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/323113
Commit-Queue: Leandro Lovisolo <f558143c2568be8d55575d13f30a1fc5cb8009d5@google.com>
Reviewed-by: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@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