The bike kick is actually a fairly common move in kung fu movies (Though it tends to look more like Hotaru's "grasshopper kick" because people can't float on their butts in real life), that's probably where Boon and Tobias got the idea when they gave it to Liu.
Hell, Scorpion does one to Sub-Zero (or vice versa, I forget which) in Annihilation.

Given both the LEGO MOVIE and MK are WB properties, and I can't remember her exact style she done it, it would not be out if the ordinary to assume it was more-so based on the Mortal Kombat version than any other property. It is safe to assume the MK version was probably taken from Hong Kong and martial arts in general, since Boon/Tobias did take from these sources, but TLM would have likely taken the move from MK, especially if she's flying across the screen as she does it.

I didn't notice but wow the lego movie was awesome.

Also, Gorostilllives what the fuck is in your sig? ^^^

It's my book called Model Combat. The cover depicts two bikini-clad women in combat, the blonde is stabbing the brunette with a knife.