Fix G3 Build

I need to add a presubmit that verifies our BUILD.bazel files
(i.e. the new ones) have the appropriate header.

Change-Id: I368d8e773aa59ff17b6d81812c67cb849c0a08fc
Bug: skia:13211
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/536881
Reviewed-by: Ravi Mistry <rmistry@google.com>
2 files changed