Moving native MIDI JNI init to AndroidRuntime.cpp.

Remove (non-working) lazy init in midi.cpp

Bug: 79464070
Test: Verify function with NativeMidiTestbed app.
Change-Id: I30182d19d205b4ab952d622824f1a63ab1fef72e
diff --git a/core/jni/Android.bp b/core/jni/Android.bp
index 302189f..d4903d8 100644
--- a/core/jni/Android.bp
+++ b/core/jni/Android.bp
@@ -165,6 +165,7 @@
         "android_media_JetPlayer.cpp",
         "android_media_MediaMetricsJNI.cpp",
         "android_media_MicrophoneInfo.cpp",
+        "android_media_midi.cpp",
         "android_media_RemoteDisplay.cpp",
         "android_media_ToneGenerator.cpp",
         "android_hardware_Camera.cpp",