Fix MAKO::check_music()

This fixes infinite loop in the opening demo of Only You, waiting for
the end of the music.

android/app/src/main/java/io/github/kichikuou/system3/GameActivity.kt

@@ -195,6 +195,10 @@ private class CddaPlayer(private val playlistPath: File) {
     private val player = MediaPlayer()
     private var playerPaused = false
 
+    init {
+        player.setOnCompletionListener { currentTrack = 0 }
+    }
+
     fun start(track: Int, loop: Boolean) {
         val f = playlist.elementAtOrNull(track - 1)
         if (f.isNullOrEmpty()) {
@@ -251,6 +255,10 @@ private class MidiPlayer {
     private var playing = false
     private var playerPaused = false
 
+    init {
+        player.setOnCompletionListener { playing = false }
+    }
+
     fun start(path: String, loop: Boolean) {
         try {
             player.apply {