Add bionic preinit test helper binaries to CTS.

Bug: http://b/35885875
Test: builds
Change-Id: I0570f52ab477c5f3f1180a238200aa7f99cc7d16
diff --git a/tests/tests/bionic/Android.build.copy.libs.mk b/tests/tests/bionic/Android.build.copy.libs.mk
index 4a01be3..efd7e93 100644
--- a/tests/tests/bionic/Android.build.copy.libs.mk
+++ b/tests/tests/bionic/Android.build.copy.libs.mk
@@ -103,6 +103,8 @@
   prebuilt-elf-files/libtest_invalid-zero_shstrndx.so \
   prebuilt-elf-files/libtest_invalid-textrels.so \
   prebuilt-elf-files/libtest_invalid-textrels2.so \
+  preinit_getauxval_test_helper/preinit_getauxval_test_helper \
+  preinit_syscall_test_helper/preinit_syscall_test_helper \
   private_namespace_libs_external/libnstest_private_external.so \
   private_namespace_libs/libnstest_dlopened.so \
   private_namespace_libs/libnstest_private.so \