BUG: TestingExtractSliceImageFilterTest v3 direction strategy.

The DirectionCollapseToStrategy is different with v3 compatibility on per
the constructor.

Change-Id: I929f1a64d95958e0c280a3290ef6169dd519714e
Merge topic 'testing-compatibility'

808c9684 BUG: TestingExtractSliceImageFilterTest v3 direction strategy.