Summary:
valgrind_test is the correct way to run valgrind tests.
this is becasue we need to force DISABLE_JEMALLOC
Test Plan: Running sandcastle and contrun
Reviewers: IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65451