The balance is zero because Armory hasn't done preparing its database yet since Bitcoin Core isn't synced.
All you need to do is to wait for it to fully sync in order for your transaction to appear.
If both Armory and Bitcoin Core are configured with default data directories and you have enough free space in that dir (about 600GB+ total),
simply running Armory and let it manage Bitcoin Core should be sufficient to fully sync the wallet within the estimated time you saw in Bitcoin Core.
If you do not want to download and store all that data, follow to the link provided by Bitmaxz above.