Rewrite testNetworkFailedRollback

This is an effort to fix flaky StagedRollbackTest.

ag/9614192 adds support for native file path to TestApp so now we can
install network stack package using install.lib which provides better
tools for logging and synchronization than shell commands. This will
facilitate debugging flakiness.

Also move other code to device tests for the same reason.

Bug: 143211397
Test: atest StagedRollbackTest
Change-Id: I971618da3defade4693be154ab523f1cbfea5b7c