[Status Bar] Old pipeline: Correctly mark carrier merged as validated.

This is a very targeted fix because we expect the old pipeline to be
able to be deleted in an upcoming release, so we don't want to
re-architect the world.

Bug: 225902574
Test: atest NetworkControllerWifiTest (The `vcnOnlyOnUnderlyingNetwork`
test fails without this fix and passes with it.)
Test: manual: verify QS tile works correctly in non-carrier merged
scenarios
Test: adb shell dumpsys activity service
com.android.systemui/.SystemUIService NetworkController still works and
has the `isDefaultConnectionValidated` column
Change-Id: I9bc007f47b991a20ca9caa85af839963f268486a

Change-Id: I2371b76a3a3a4fe679444122385ee97c7f57e2b3