the places searchbox page at https://developers.google.com/maps/documentation/javascript/examples/places-searchbox from which the html of KmlLayerTest.html is derived states at the bottom:
"Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates."
and the Apache 2.0 license at https://www.apache.org/licenses/LICENSE-2.0 states:
"4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions:
You must give any other recipients of the Work or Derivative Works a copy of this License; and
You must cause any modified files to carry prominent notices stating that You changed the files; and
You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; [...]"
So it looks like that file, being derived from the sample code on the Places Searchbox page, needs some license info added to it meeting these (and any other) requirements of the Apache 2.0 license.