Enable zcat in the host toybox.

toybox tar will try to run zcat (which we don't currently have) rather
than `gzip -dc` (which we do). Easiest thing to do is just have zcat too.

Bug: http://b/150370062
Test: toybox zcat
Change-Id: I13b8c5e4c5ac9dfbc7467b6744da2ca76141f5d3
Merged-In: I13b8c5e4c5ac9dfbc7467b6744da2ca76141f5d3
(cherry picked from commit 250a80c9dcdf5a310659c5820acc07564ba8f86d)
6 files changed