Modularize VoiceInteraction/SoundTrigger

Rather than building VoiceInteraction monolithically, split out
SoundTrigger.

This allows for better build performance, more localized testing,
specific build flags, etc.

Split out the middleware in a static lib for now, but don't expose it
as such, since it will be refactored into SoundTrigger soon.

Fixes: 277374624
Test: Compiles (build changes only)
Change-Id: I631d073d81e578c70b033d0a43543ef89dda9194
diff --git a/services/tests/voiceinteractiontests/Android.bp b/services/tests/voiceinteractiontests/Android.bp
index 986fb71..e704ebf 100644
--- a/services/tests/voiceinteractiontests/Android.bp
+++ b/services/tests/voiceinteractiontests/Android.bp
@@ -40,6 +40,7 @@
         "platform-test-annotations",
         "services.core",
         "services.voiceinteraction",
+        "services.soundtrigger",
         "servicestests-core-utils",
         "servicestests-utils-mockito-extended",
         "truth-prebuilt",