Revert "Add define to use customize vulkan header."

This reverts commit a492eb0e1f08311bfa47f46c660144e7bc8a6c0e.

Reason for revert: Breaking Android roll (b/c builds tools?)

Original change's description:
> Add define to use customize vulkan header.
> 
> Bug: skia:
> Change-Id: Ia87c81a54603a02b2f8f51a735bf173a49afe6c7
> Reviewed-on: https://skia-review.googlesource.com/81121
> Commit-Queue: Greg Daniel <egdaniel@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

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

Change-Id: I80a685bf88af909865f274ffc61686be57e8c313
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/81740
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
3 files changed