[releng] CQ 8204: Rename maven-license-plugin files to header-*.txt

This issue was raised during CQ 8204 (our initial contribution): The old
name (license-*.txt) might lead consumers to mistake these files for the
licenses themselves.

Change-Id: I8252c4b6d9c4fd12f27e82a280a71201fdac1008
Signed-off-by: Andreas Sewe <andreas.sewe@codetrails.com>
Bug 437195: Enable multiple datums persistence

Change-Id: I2b227fd67d4045a2b11f3c532d80ff253c7bcc7a
Signed-off-by: Yasser Aziza <yasser.aziza@gmail.com>
Signed-off-by: Andreas Sewe <andreas.sewe@codetrails.com>