Revert "Put the right defaults for test lib."

This reverts commit d8d0f19c.

Reason for revert: Test segfaults here:
https://build.chromium.org/p/client.art/builders/bullhead-armv7-gcstress-ndebug/builds/1719/steps/test%20optimizing/logs/stdio

Change-Id: I6501aba3b8b666881b8457d89b27526d43a69e2b