QAART-402 Fixing the test by using the correct content

The test previously was selecting an image with unicode file name hence the UnknownFormatConversionException getting thrown.
Changed the way to select the image since the ordering of the image is sorted by last upload, this will be affected by other tests which test for image upload. The better way is to select the image by the file name.

https://wikia-inc.atlassian.net/browse/QAART-402
Switched to use a dedicated file that is not being use in other tests