In LEGO Star Wars: The Force Awakens (mobile version ios android 3ds), Oscillator Bombing Run, how do you get the minikits

You can toss seeds in midair on the Android version of the game. Simply fly slightly above the location where you wish to toss the seed, release the finger guiding Liang, and quickly tap on the seed canister (you can also try tapping the canister with another finger, but in my experience on the tablet this doesn't always work).

The game will pause while you choose your seed, and Liang's jetpack will activate automatically after you choose your seed to slow his descent while you aim and throw. It takes a bit of practice, so try practising ahead in a safe area, but it is relatively easy to execute once you get the hang of it.

On the Android version, you can't get this achievement, because the required button doesn't exist.

It was added in a fairly recent version, presumably by mistake - it was removed again in today's update, which seems to confirm that it should never have shown up on Android.