Allow nested jUnit suites
Allow nested jUnit suites

Some providers will nest jUnit suites to subdivide jUnit output.

Signed-off-by: Steve Kuznetsov <a7da0fca91d9933d2725d731a48cabdc9e8ffd7a@redhat.com>

GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid,GoogleCloudPlatform/testgrid