Revert^3 "Reduce libcore parallelism for host"

This reverts commit f2f924222a4ec748bdeab45c4de7d88ae477c594.

Reason for revert: It made the tests green after all.
(I still consider this as only short-term work-around)

Change-Id: Id027c5ef437abf7b2018374ded5c9529a6bb4867
1 file changed