Turn off file grouping in test step that reads converted DICOM files

This prevents test run times from depending on the contents of the temp directory.
Without this change, some builds failed as the tests didn't finish.

Author: melissalinkert

components/formats-bsd/test/loci/formats/utests/dicom/ProvidedMetadataTest.java

@@ -91,6 +91,7 @@ public Path doConversion(String jsonMetadata) throws FormatException, IOExceptio
 
   public List<DicomTag> getTags(Path dicomFile) throws FormatException, IOException {
     DicomReader reader = new DicomReader();
+    reader.setGroupFiles(false);
     reader.setId(dicomFile.toString());
     List<DicomTag> tags = reader.getTags();
     reader.close();