Revert "disable seccomp"

Confirmed that libminijail checks for seccomp support in
kernel before attempting to apply a filter.

This reverts commit 1ab2f2d0a6208ec9b6bb7e8b130efa9b70737f98.

Change-Id: I33a412bf9c836ca56669bb83506a8774f6607188
1 file changed