DeleteTempJarTest.java enhancement: to remove the dependency on test output

This is a follow-up enhancement to
java/util/zip/ZipFile/DeleteTempJarTest.java
which was refactored from shell scrip test deletetempjar.sh (in JDK-8209930), it follows previous workflow that to get the filename from test output.

This "can be a bit fragile sometimes to use the output of the sub-process. Just thinking about warnings or other output in non-product builds that might be sent to stdout rather than stderr. An alternative would be DeleteTempJarTest to create a listener socket and have DeleteTempJar connect to send the file name"