Unmarshalling fails for xml that contains xmlns starting from version 2.6.3

[FieteO]

Describe the bug
I am working on a project that is still on eclipselink 2.6.2. When updating to anything higher, I observe an issue with unmarshalling xml's that contain a namespace, i.e:

<model xmlns="http://org.onap.aai.inventory/v14">
</model>

There is no explicit exception as such, but the resulting DynamicEntity will have the object keys, but without value (such that entity.get("modelId") returns null.

To Reproduce
Steps/resources to reproduce the behavior:

• EclipseLink version: 2.6.3
• Java/JDK version: Java 8
• Entity source (mainly applied annotations)
  For problem in MOXy (JAXB implementation)
  • schema-definitions are defined in a separate schema-service
  • based on that, a DynamicJAXBContext is created for each schema version (v10-v29)
  • NodeIngestor holds that context. It is retrieved with nodeIngestor.getContextForVersion(new SchemaVersion("v14")) (see test case)
• Code example which leads into bug like:

I have created the following change request to reproduce the behaviour: Add test case that tests jaxb unmarshalling of xml
It contains the following test:

@Test
public void moxyTest() throws IOException, JAXBException{
    String xmlModelPayload = new String(Files.readAllBytes(Paths.get("src/test/resources/payloads/resource/network-service.xml")));
    DynamicJAXBContext jaxbContext = nodeIngestor.getContextForVersion(new SchemaVersion("v14"));
    final Object clazz = jaxbContext.newDynamicEntity("Model");
    Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
    DynamicEntity entity = (DynamicEntity)unmarshaller.unmarshal(new StreamSource(new StringReader(xmlModelPayload)), clazz.getClass()).getValue();
    assertEquals("d821d1aa-8a69-47a4-aa63-3dae1742c47c", entity.get("modelInvariantId"));
    assertEquals("service", entity.get("modelType"));
}

To check it out and run it:

• Clone the project with git fetch https://gerrit.onap.org/r/aai/aai-common refs/changes/46/138646/2 && git checkout -b change-138646 FETCH_HEAD
• make sure you are using Java 8 (i.e by prefixing the following command with JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/)
• Run cd aai-core && mvn test -Dcheckstyle.skip -Dtest=MoxyEngineTest#moxyTest
• The test should pass
• Change the eclipse.persistence.version in the pom.xml to 2.6.3 and rerun the test
• The test should fail
• Optionally mvn test [...] -Dmaven.surefire.debug can be used to enable remote debugging

Expected behavior
That unmarshalling works for both versions, such that dynamicEntity.get("myAttribute") returns a value != null.