MIDI: Flag virtual UMP

This CL flags the new virtual UMP MIDI APIs in UmpMidiDeviceService.
This CL also adds a check in MidiService to enforce the flag.

Bug: 291115176
Bug: 301713211
Test: atest MidiEchoTest
Test: adb logcat *:S MidiService:V
Change-Id: I29d12ea35a4a4231a0e67e4abcef2a149ee48ebc
diff --git a/services/midi/Android.bp b/services/midi/Android.bp
index 5adcfba..4b5f8a7 100644
--- a/services/midi/Android.bp
+++ b/services/midi/Android.bp
@@ -19,4 +19,7 @@
     defaults: ["platform_service_defaults"],
     srcs: [":services.midi-sources"],
     libs: ["services.core"],
+    static_libs: [
+        "aconfig_midi_flags_java_lib",
+    ],
 }