Revert "Update skia to use ifdefs for Vulkan code instead of dummy header"

This reverts commit c0f8e426c59eec6c720b8e1329dcb966cf1b6800.

Reason for revert: Experiment to see if this will unblock the Android roll

Original change's description:
> Update skia to use ifdefs for Vulkan code instead of dummy header
> 
> Bug: skia:6721
> Change-Id: I80a4c9f2acc09c174497f625c50ed12a8bb76505
> Reviewed-on: https://skia-review.googlesource.com/19547
> Reviewed-by: Mike Klein <mtklein@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,mtklein@google.com,bsalomon@google.com

Change-Id: Ib51c1672570f2071a17b6fbde692a5174b0358ce
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:6721
Reviewed-on: https://skia-review.googlesource.com/19724
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
8 files changed