Set restrict local network aconfig flag for 26q2 dates

Local net protections is introduced in B as a developer opt-in, on dev
builds; the feature flag is meant to be used when enforcement begins in
2026

Bug: 396116600
Test: atest ConnectivityCoverageTests:android.net.connectivity.com.android.server.connectivity.PermissionMonitorTest
Change-Id: Id5e7a7cf825f10f90edd600ea2567cfe6efd2e98
3 files changed