Fix failure message from jtreg gtest wrapper

The current report of a gtest run (when jtreg is used as wrapper as it is in nightly testing) does not state which test or how it fails.

This needs to be improved to get faster help when looking at results.

We need something better than to have this as guidance for all tests:
   R--E "native/GTestWrapper.java" Exception java.lang.RuntimeException: Expected to get exit value of [0]

There are different ways to solve this, both to improve the jtreg test and to change to run without jtreg and use the junit.xml that gtest delivers.