[proberk] Update prober for piet-gpu.
[proberk] Update prober for piet-gpu.

Bug: skia:13520
Change-Id: Ic73f595744e7d4bfaabb98071f81d8d867b859d6
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/557590
Auto-Submit: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Reviewed-by: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>
Commit-Queue: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@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