Revert "Revert "libbinder: Replace deprecated utils/threads.h header""

This reverts commit a643e2dabde445e257dc97e9ce81436497f6b2ee.

Reason for revert: Fixed libvrflinger

Change-Id: I2df02b571b49fe040958ee2c8236605426315d68
diff --git a/libs/binder/BufferedTextOutput.h b/libs/binder/BufferedTextOutput.h
index fdd532a..57e03cb 100644
--- a/libs/binder/BufferedTextOutput.h
+++ b/libs/binder/BufferedTextOutput.h
@@ -18,8 +18,8 @@
 #define ANDROID_BUFFEREDTEXTOUTPUT_H
 
 #include <binder/TextOutput.h>
-#include <utils/threads.h>
 #include <sys/uio.h>
+#include <utils/Mutex.h>
 
 // ---------------------------------------------------------------------------
 namespace android {