[EnterprisePolicy] Migrate policies to AutofillSettings.

This CL introduces a migration path for the deprecated
`AutofillAddressEnabled` and `AutofillCreditCardEnabled` boolean
policies, transitioning their behavior into the new unified
`AutofillSettings` list policy.

Implementation details:
- Introduces `AutofillSettingsPolicyHandler`, inheriting from `SimpleSchemaValidatingPolicyHandler`, to handle the list schema validation and preference mapping.
- Automatically synthesizes wildcard domain block rules (e.g., `url_pattern: "*"`) for `contact_info` and `payments` if their respective legacy policies are set to disabled (`false`).
- Appends these synthesized wildcard rules to any site-specific rules explicitly configured by the admin via the new `AutofillSettings` policy, merging them into the `kAutofillTypesBlocked` preference.
- Maintains backward compatibility by continuing to map the legacy boolean policies to their original preferences (`kAutofillProfileEnabled`, `kAutofillCreditCardEnabled`).

Design doc: go/url-data-type-autofill-enterprise-policy

Bug: 466345561
Change-Id: Ib9197c11e40feb6d900950d3ddca4f49df09ec9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7958598
Reviewed-by: Christoph Schwering <schwering@google.com>
Commit-Queue: Luchen Peng <luchenpeng@google.com>
Reviewed-by: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Reviewed-by: Norge Vizcay <vizcay@google.com>
Cr-Commit-Position: refs/heads/main@{#1652438}