Currently the Android MIDI support is conditionally included depending on the project settings (AndroidMidi.java vs. AndroidMidiFallback.java), based on the minimum supported SDK version. However, I believe the correct way to do this would be to check the version dynamically, as long as the target SDK version is high enough. See http://developer.android.com/training/basics/supporting-devices/platforms.html#version-codes
Also, there doesn't seem to be a selection for the target sdk version in introjucer...