Fix unit tests that were causes vulkan unitialized memory warnings in validation

Bug: skia:
Change-Id: Id9df92b76c9f948f41f4108bcecdb2687233f841
Reviewed-on: https://skia-review.googlesource.com/110761
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
5 files changed