UFAL/S3 synchronization should be more reliable and less error-prone

[milanmajchrak]

Validate the sync.enabled with assetstore.index.primary when:

• downloading directly the bitstream
• Creating the Item: https://github.com/dataquest-dev/DSpace/blob/dtq-dev/dspace-api/src/main/java/org/dspace/storage/bitstore/SyncBitstreamStorageServiceImpl.java#L72
• .. ?