Revert "Audio V4: Split system and vendor Audio.h"

This reverts commit 49c56de516b4e9556ae1b0af0ccfa7d695f5807b.

Reason for revert: Breaks the build of multiple devices

Change-Id: Iebd868467948b8afa5907462ccc0720cd9c4871e
diff --git a/soundtrigger/2.0/default/Android.bp b/soundtrigger/2.0/default/Android.bp
index 21e50e1..cc20f91 100644
--- a/soundtrigger/2.0/default/Android.bp
+++ b/soundtrigger/2.0/default/Android.bp
@@ -16,7 +16,10 @@
 cc_library_shared {
     name: "android.hardware.soundtrigger@2.0-core",
     defaults: ["hidl_defaults"],
-    vendor: true,
+    vendor_available: true,
+    vndk: {
+        enabled: true,
+    },
     srcs: [
         "SoundTriggerHalImpl.cpp",
     ],
@@ -34,7 +37,7 @@
     ],
 
     header_libs: [
-        "android.hardware.soundtrigger.legacy@2.0",
+        "libaudio_system_headers",
         "libhardware_headers",
     ],
 }