StreamOut: Fix STREAM_EVENT_CBK_TYPE_CODEC_FORMAT_CHANGED

Use audio_metadata_byte_string_len method in asyncEventCallback.

Test: atest metadata_tests
Bug: 186894288
Change-Id: I04914bc5b2c778002b53b8f8da5bf29fff5c80f8
diff --git a/audio/core/all-versions/default/Android.bp b/audio/core/all-versions/default/Android.bp
index f61964e..615655d 100644
--- a/audio/core/all-versions/default/Android.bp
+++ b/audio/core/all-versions/default/Android.bp
@@ -56,6 +56,7 @@
         "android.hardware.audio-impl_headers",
         "android.hardware.audio.common.util@all-versions",
         "libaudioclient_headers",
+        "libaudioutils_headers",
         "libaudio_system_headers",
         "libhardware_headers",
         "libmedia_headers",
diff --git a/audio/core/all-versions/default/StreamOut.cpp b/audio/core/all-versions/default/StreamOut.cpp
index a089f6b..4fe6601 100644
--- a/audio/core/all-versions/default/StreamOut.cpp
+++ b/audio/core/all-versions/default/StreamOut.cpp
@@ -28,6 +28,7 @@
 
 #include <HidlUtils.h>
 #include <android/log.h>
+#include <audio_utils/Metadata.h>
 #include <hardware/audio.h>
 #include <util/CoreUtils.h>
 #include <utils/Trace.h>
@@ -742,7 +743,11 @@
     switch (event) {
         case STREAM_EVENT_CBK_TYPE_CODEC_FORMAT_CHANGED: {
             hidl_vec<uint8_t> audioMetadata;
-            audioMetadata.setToExternal((uint8_t*)param, strlen((char*)param));
+            // void* param is the byte string buffer from byte_string_from_audio_metadata().
+            // As the byte string buffer may have embedded zeroes, we cannot use strlen()
+            // but instead use audio_utils::metadata::dataByteStringLen().
+            audioMetadata.setToExternal((uint8_t*)param, audio_utils::metadata::dataByteStringLen(
+                                                                 (const uint8_t*)param));
             result = eventCallback->onCodecFormatChanged(audioMetadata);
         } break;
         default: