Move comment to license_note

Comments not preserved during refresh.

Test: m nothing
Change-Id: I62e9fa90fe9bed2b537044b50fad7b96c0d5d5bc
diff --git a/METADATA b/METADATA
index bcdbd44..9b4842c 100644
--- a/METADATA
+++ b/METADATA
@@ -10,9 +10,7 @@
     value: "https://github.com/httplib2/httplib2.git"
   }
   version: "v0.18.1"
-  # would be NOTICE save for:
-  #   test/other_cacerts.txt
-  #   doc/html/_static/jquery.js
+  license_note: "would be NOTICE save for: test/other_cacerts.txt and doc/html/_static/jquery.js"
   license_type: RESTRICTED
   last_upgrade_date {
     year: 2020