Use String8/16 c_str (mainline modules)

Bug: 295394788
Test: make checkbuild
Change-Id: Ia266bccfc9100da25d8605d93c1298a341d2b11a
diff --git a/media/module/libmediatranscoding/TranscodingSessionController.cpp b/media/module/libmediatranscoding/TranscodingSessionController.cpp
index ea3e518..e9d19d3 100644
--- a/media/module/libmediatranscoding/TranscodingSessionController.cpp
+++ b/media/module/libmediatranscoding/TranscodingSessionController.cpp
@@ -421,7 +421,7 @@
         dumpSession_l(session, result, true /*closedSession*/);
     }
 
-    write(fd, result.string(), result.size());
+    write(fd, result.c_str(), result.size());
 }
 
 /*