Fix problem with phoenix JUnit reporting

The jenkins JUnit reporter can not be set up to report on multiple
directories unless the directories are always present. An empty
directory means the test failed. This fix partially backs
out the change Ic10d912c0661fca8bfc6284e064163f1934abd3f and
fixes the phoenix test to always use the same directory for
reporting test results.

Change-Id: I084c7d0cadb635c29553e2200e0c78622ac39246