EAP6 fails to load valid-connection-checker class which used to work in EAP5

Issue

• After creating the datasource with the "valid-connection-checker" class as "org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker" JBoss EAP6 starts throwing WARNNING messages in the server.log files as following:

WARN  [org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory] (host-controller-connection-threads - 6) Exception trying to create valid connection checker (disabling):: java.lang.Exception: Unable to load: org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker
    at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnectionFactory.loadPlugin(BaseWrapperManagedConnectionFactory.java:1103) [ironjacamar-jdbc-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]
    at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnectionFactory.isValidConnection(BaseWrapperManagedConnectionFactory.java:1180) [ironjacamar-jdbc-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]
    at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.checkValid(BaseWrapperManagedConnection.java:461) [ironjacamar-jdbc-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.matchManagedConnections(LocalManagedConnectionFactory.java:507) [ironjacamar-jdbc-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]
    at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.getConnection(SemaphoreArrayListManagedConnectionPool.java:282) [ironjacamar-core-impl-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]
    at org.jboss.jca.core.connectionmanager.pool.AbstractPool.getSimpleConnection(AbstractPool.java:397) [ironjacamar-core-impl-1.0.11.Final-redhat-1.jar:1.0.11.Final-redhat-1]