Implement the soundtrigger_middlewware service

This service is intended to replace:
frameworks/av/include/soundtrigger/ISoundTriggerHwService.h

This change only adds the replacement service, follow up
changes migrate the clients to use the new service and remove
the old one. The new service is feature-equivalent to the new
one, but offers the following advantages:
- AIDL interface (as opposed to hand-written parceling code).
- Pure Java implementation all the way to the HAL.
- Better documentation.
- Rigorous error handling.
- Unit tests.
- Reduced code complexity (less layers, better separation of
  concerns).
- Permission-based security model (as opposed to some baked-in
  assumptions about process affinity).

Change-Id: I79f4eff105d3e6245990be068b933d4d48c35a0d
Bug: 142070343

services/java/com/android/server/SystemServer.java

@@ -147,6 +147,7 @@ import com.android.server.security.KeyAttestationApplicationIdProviderService;
 import com.android.server.security.KeyChainSystemService;
 import com.android.server.signedconfig.SignedConfigService;
 import com.android.server.soundtrigger.SoundTriggerService;
+import com.android.server.soundtrigger_middleware.SoundTriggerMiddlewareService;
 import com.android.server.statusbar.StatusBarManagerService;
 import com.android.server.storage.DeviceStorageMonitorService;
 import com.android.server.telecom.TelecomLoaderService;
@@ -1544,6 +1545,10 @@ public final class SystemServer {
             }
             t.traceEnd();
 
+            t.traceBegin("StartSoundTriggerMiddlewareService");
+            mSystemServiceManager.startService(SoundTriggerMiddlewareService.Lifecycle.class);
+            t.traceEnd();
+
             if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_BROADCAST_RADIO)) {
                 t.traceBegin("StartBroadcastRadioService");
                 mSystemServiceManager.startService(BroadcastRadioService.class);