Switch to libbase SilentDeathTest.

Bug: http://b/184955378
Test: treehugger
Change-Id: Ie0849224074da92203340a741a86a24a4a3702c2
diff --git a/tests/threads_test.cpp b/tests/threads_test.cpp
index 5fafff3..c1e9b12 100644
--- a/tests/threads_test.cpp
+++ b/tests/threads_test.cpp
@@ -60,7 +60,8 @@
 
 #include <thread>
 
-#include "BionicDeathTest.h"
+#include <android-base/silent_death_test.h>
+
 #include "SignalUtils.h"
 
 TEST(threads, call_once) {
@@ -361,7 +362,7 @@
 #endif
 }
 
-class threads_DeathTest : public BionicDeathTest {};
+using threads_DeathTest = SilentDeathTest;
 
 TEST(threads_DeathTest, thrd_exit_main_thread) {
 #if !defined(HAVE_THREADS_H)