Update VpnTest#testDefault to check other uid blocked status

On V+, ConnectivityService generates blockedReasons based on bpf map
contents even if the uid does not exist on device.
So if allowlist chain (e.g. background chain) is enabled, network access
from non existing uid is considered blocked.

Test: VpnTest#testDefault
Bug: 342557183
Change-Id: I7776c1ea0d546e53a3495d4db6d42c573b6d1f7f
1 file changed