Add license_note am: 30f04785be am: ce8a31e760 am: 33ae2c60fe

Original change: https://android-review.googlesource.com/c/platform/external/google-fonts/zilla-slab/+/2011798

Change-Id: If3404960cf762398317b49b9a81a2b1c5bbd174f
diff --git a/METADATA b/METADATA
index e46d6f8..6888df3 100644
--- a/METADATA
+++ b/METADATA
@@ -17,5 +17,6 @@
   }
   version: "ab442e488a2962f4e520a7a384ba1926d3db1994"
   last_upgrade_date { year: 2018 month: 3 day: 11 }
+  license_note: "contains OFL fonts"
   license_type: BY_EXCEPTION_ONLY
 }