When making this script deterministic we accidentally changed it so that none of the entries in the output zip file were compressed. Re-add the compression. Adding the compression makes atest go from 67M to 34M, at the cost of 0.33s startup time instead of 0.28s. Test: Presubmits Change-Id: I4e58eb76235ddabf0195694cdd3644f26b7e84ec