Properly describe exception

Previously we used DetachCurrentThread which raised a SIGABRT from
within ART. The new approach is to use ExceptionDescribe and exit.

Bug: 20640601
Change-Id: Ia6c2345b656b2ada29d262399798a6ed717a7f85

core/jni/android_util_Binder.cpp

@@ -202,8 +202,7 @@ static void report_exception(JNIEnv* env, jthrowable excep, const char* msg)
          */
         JavaVM* vm = jnienv_to_javavm(env);
         env->Throw(excep);
-        vm->DetachCurrentThread();
-        sleep(60);
+        env->ExceptionDescribe();
         ALOGE("Forcefully exiting");
         exit(1);
     }