fdo#79676: Fix the Java UNO API test with regard to chart tests.

The Java tests rely on the "undocumented" behavior that, when loading an empty
chart document, the chart automaticallly created a "default chart" which is a
column chart with many of its properties filled.  Unfortunately this behavior
caused ugly side effects when loading documents with charts via flat ODF
filter.

I believe fixing the test this way is the right fix.

Change-Id: If3e6c8979da9d0731346ebeedc23c0d3363e83fd
(cherry picked from commit d44b58beed743871df03909e7d9545e488f3d7c8)
Signed-off-by: Michael Stahl <mstahl@redhat.com>