Enable default background network restrictions

This reverts commit 951e4bd8f653a9be2d96c3258201b708ddef8476 and commit
b6a3ff2d76590c4d24710e2c38360f74e0c56cd8

Test: atest CtsHostsideNetworkTests
Test: atest resolv_integration_test
Test: atest FrameworksServicesTests:NetworkPolicyManagerServiceTest

Bug: 304347838
Change-Id: I0c8e0c713f0a7aae7f0ab99e42d97d5bf770bc47
2 files changed