Audio HAL: Add optional Destination to SinkMetadata

Currently this is used to indicate the output device
when the input stream is from an intermediate processing
module like MSD.

Bug: 120859615
Test: make
Change-Id: I60bac5c24a263ab0b8965e9dbf9514445e88c270
diff --git a/audio/effect/5.0/Android.bp b/audio/effect/5.0/Android.bp
index d60d94a..78b950e 100644
--- a/audio/effect/5.0/Android.bp
+++ b/audio/effect/5.0/Android.bp
@@ -26,6 +26,7 @@
     interfaces: [
         "android.hardware.audio.common@5.0",
         "android.hidl.base@1.0",
+        "android.hidl.safe_union@1.0",
     ],
     types: [
         "AudioBuffer",