NOTICE files use incorrect wording "developed by" instead of "developed at"

The NOTICE files currently use the incorrect wording "developed by The Apache Software Foundation".

As it can be shown in the following links (and also from other JIRA tickets) the correct wording is "developed at".

https://www.apache.org/legal/src-headers.html#notice
https://www.apache.org/legal/release-policy.html#notice-required