(re)integrating Native MIDI API into NDK - base API

Implement native MIDI API (amidi)

Bug: 30252756
Bug: 37090545

Test: manual - Connect PreSonus AudioBox 22VSL and run tests in NativeMidiTestbed app.
Verify MIDI messages sent to external MIDI synthesizer.
Verify MIDI messages received from external MIDI synthesizer.
CTS

Change-Id: I7bb02b8926d01090132ce873c785b5323a9fa5f8