Fix PDM::IsAutofillSyncToggleAvailable()

crrev.com/c/5434054 added a feature flag that enables CONTACT_INFO for
users under parental supervision. However, the CL missed updating the
equivalent logic in the PDM, which is used to decided whether the
toggle in sync settings should be visible. This CL does so.

Bug: b/40259988
Change-Id: I966e9eae45457c64d0723ec357b321a861625442
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5435245
Commit-Queue: Florian Leimgruber <fleimgruber@google.com>
Reviewed-by: Dmitry Vykochko <vykochko@google.com>
Cr-Commit-Position: refs/heads/main@{#1284376}