Format public.bzl

Bug: skia:8210
Change-Id: I215d7a85ad3cee63df78128d8bd00d6f7b67fd99
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/259430
Reviewed-by: Ben Wagner aka dogben <benjaminwagner@google.com>
Commit-Queue: Ben Wagner aka dogben <benjaminwagner@google.com>
diff --git a/public.bzl b/public.bzl
index 87aee5d..f4546f7 100644
--- a/public.bzl
+++ b/public.bzl
@@ -408,7 +408,7 @@
             "src/**/*.h",
             "src/gpu/mtl/**/*.mm",
             "third_party/**/*.h",
-        ]
+        ],
     ) + [
         "src/image/SkSurface_GpuMtl.mm",
     ]