Created constants for tested browser versions (#12786)

Change-Id: I8f349bb3c338bb7e9073944891436edac5ee1bb1
Allow running tests locally by overriding runLocally() (#12786)

Uses Firefox either from path or from the location given using firefox.path in /work/run-eclipse-run-selected-test.properties

Change-Id: I29faa94cac4c978792a8fab9db338048553d166a