MoltenVk fix for fuchsia again.

Bug: skia:
Change-Id: I57365b69c4c764079512dce9e6d1bb624a199d1f
Reviewed-on: https://skia-review.googlesource.com/129449
Commit-Queue: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Greg Daniel <egdaniel@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>