This is EASY - if your AC cord to the wall - are the same between the 2 - and the charging cable to the eBike battery are the same - YOU ARE GOOD TO GO.
You bought a 1.7Amp charger - compared to the 2Amp charger trhan came with the bike - your charging time with the new Aliexpress charger will be 15% more than the original (if charger specs prove accurate) - which is fine as your battery will not overheat from charging a hair slower !
If you bought a 4Amp charger from AliExpress - if spec accurate your charging time would be Cut-In-Half but your battery would heat up much higher than 2Amp - so that :"facter charge" will diminish the life and strength of that battery a LOT.
Keep the beat !