Fix missing comma in public.bzl

Change-Id: I6b2288c890a3290bf3ed31044219e1c4d9f0f0fa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/274203
Auto-Submit: Nathaniel Nifong <nifong@google.com>
Reviewed-by: Nathaniel Nifong <nifong@google.com>
Commit-Queue: Nathaniel Nifong <nifong@google.com>
1 file changed