AudioFlinger: Fix tee logging

Missing header file hidden by compile flag.

Test: Compilation is fixed when flag enabled
Bug: 78310170
Change-Id: Ie938193c5d87de04f22318a8fb4fffb4a4412a53
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 3c4f500..76b29c9 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -56,6 +56,7 @@
 #include <system/audio_effects/effect_aec.h>
 
 #include <audio_utils/primitives.h>
+#include <audio_utils/string.h>
 
 #include <powermanager/PowerManager.h>