In the Java layer? About the only thing you can do is ensure that you're using the devices native sampling rate: typically 48 kHz for phones, and 44.1 kHz for tablets. Non-native sampling will induce a rather large latency hit. The buffering + buffer size stuff, unfortunately, is really only accessible in native IIRC.

To be completely honest, it's been a long time since I've messed with audio-stuff on the Java-side, so not sure if/how much things have changed for the better.