org.eclipse.ui.tests.navigator.jst.JstPipelineTest.testJstPipeline test
fails while running with Java9

The library charset.jar is not available from Java9 onwards. As this is
a ContentProvider test, Also checking for "java.base" which is the case
for Java9.

Change-Id: Ie85e01f2b973c0e8427592127a3964168c73fffb
Signed-off-by: kalyan prasad <kalyan_prasad@in.ibm.com>