Revert "Make the network stack a persistent process."

This reverts commit 796afddd6c7012dc7f10bc2557eb06767c5d873a.

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

Bug: 131046856
Change-Id: I35ded113b31e742f13ad8523a10af3a83a111374
Merged-In: I35ded113b31e742f13ad8523a10af3a83a111374
(cherry picked from commit b2a5d855224afbffdf8a7545de2d703d9696344c)