Improve License Header by adding a clarifacation

Hi all,

thank you for your work! May I suggest the following improvement for the license header.

At the moment, the license header is as follows.

https://github.com/jakartaee/jaf-api/blob/dd51393358a3474f46774b015e438239a54e4784/api/src/main/java/jakarta/activation/ActivationDataFlavor.java#L1-L9

This header is unclear and may confuse confusion as it states that the project is licensed under ``Eclipse Distributipn License v. 1.0``, but the ``SPDX`` license identifier states the ``BSD-3-Clause``. While the equivalence is stated at [Eclipse Distribution License - v 1.0
](https://www.eclipse.org/org/documents/edl-v10.php), it is not mentioned on the Open Source Initiative website for the [``BSD-3-Clause``](https://opensource.org/license/BSD-3-Clause). This goes as far back as [``v1.2.1``](https://github.com/jakartaee/jaf-api/blob/1.2.1/activation/src/main/java/com/sun/activation/registries/LogSupport.java).

Based on this, may I suggest the following license header.

```java
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is equivalent to the BSD-3-Clause.
* The license text is available at http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
```

I am happy to open a ``PR`` myself if the new license header is approved.

Thank you in advance!

PS: The Website ``Libraries.io`` claims that [the project is licensed under the Server Side Public License v1.0 (SSPL-1.0)](https://libraries.io/maven/jakarta.activation:jakarta.activation-api/2.1.2).

Start with the license header in api/src/main/java/jakarta/activation/ActivationDataFlavor.java, then inspect related source files for the same wording. Compare the existing Eclipse Distribution License and SPDX text with the proposed clarification. Done means the affected headers consistently explain the EDL v. 1.0 and BSD-3-Clause equivalence without changing the licensing terms.

Written by the indexing model from the issue text.