Assuming that the screenshots directory suffix
* should match the configured UI locale instead of the work locale
* should not be empty if configuration says "Default - ..."
  * actually ScreenshotTest::implSaveScreenshot() explicitly tests
    (maCurrentLanguage == "en-US") and then sets the suffix to empty, so no
    other locale should exhibit the same

Change-Id: Ie4561315b67c3ade20f3947772af45e471d0752f