Revert "Make the network stack a persistent process."

This reverts commit 796afddd.

Reason for revert: breaks updatability because persistent processes are not updatable.

Bug: 131046856
Change-Id: I35ded113b31e742f13ad8523a10af3a83a111374
Merged-In: I35ded113b31e742f13ad8523a10af3a83a111374
(cherry picked from commit b2a5d855)