Import initial work on Android frontend

android/app/src/cpp/android_audio_stream.h

@@ -0,0 +1,21 @@
+#pragma once
+#include "common/audio_stream.h"
+#include <cstdint>
+
+class AndroidAudioStream final : public AudioStream
+{
+public:
+  AndroidAudioStream();
+  ~AndroidAudioStream();
+
+  static std::unique_ptr<AudioStream> Create();
+
+protected:
+  bool OpenDevice() override;
+  void PauseDevice(bool paused) override;
+  void CloseDevice() override;
+
+  // static void AudioCallback(void* userdata, uint8_t* stream, int len);
+
+  bool m_is_open = false;
+};