Move comment to license_note

Comments not preserved during refresh.

Test: m nothing
Change-Id: Iff231c8d1d311739f1ebf2768719367659202083
diff --git a/METADATA b/METADATA
index 20b25ba..05d4892 100644
--- a/METADATA
+++ b/METADATA
@@ -2,7 +2,6 @@
 #     CONSULT THE OWNERS AND opensource-licensing@google.com BEFORE
 #     DEPENDING ON IT IN YOUR PROJECT. ***
 third_party {
-  # would be RESTRICTED save for invensense license:
-  #   6515/libsensors_iio/License.txt
+  license_note: "would be RESTRICTED save for invensense license: 6515/libsensors_iio/License.txt"
   license_type: BY_EXCEPTION_ONLY
 }