Use String8/16 c_str [audio]

Bug: 295394788
Test: make checkbuild
Change-Id: Idd3610f6820093bd8710a401f87a136cc26279c5
Merged-In: Idd3610f6820093bd8710a401f87a136cc26279c5
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index b867774..1d00a34 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -167,7 +167,7 @@
             mKeyValuePairs(keyValuePairs) {}
 
         virtual  void dump(char *buffer, size_t size) {
-            snprintf(buffer, size, "- KeyValue: %s\n", mKeyValuePairs.string());
+            snprintf(buffer, size, "- KeyValue: %s\n", mKeyValuePairs.c_str());
         }
 
         const String8 mKeyValuePairs;