Adds Feature Flag for Autofill Service

[cmonfortep]

Task/Issue URL: https://app.asana.com/0/1149059203486286/1209289199349624/f

Description

Adds FFs around Autofill Service. See task for details.

Steps to test this PR

• checkout the branch
• go to AutofillServiceFeature, and remove all InternalAlwaysEnabled (otherwise is not possible to test)

Feature 1

• install the app
• Go to autofill system settings, ensure DuckDuckGo is not listed there
• open the app, go to feature flags internal setting, enable Autofill Service
• restart the app
• Go to autofill system settings, ensure DuckDuckGo is listed there
• Selected DDG

Feature 2

• Perform one test from https://app.asana.com/0/1149059203486286/1209279712661812/f on a native app
• It should not suggest you anything
• open the app, go to feature flags internal setting, enable canUpdateAppToDomainDataset and canMapAppToDomain
• restart the app
• Repeat the test from step 1
• Now you should see some suggestions (since we have enabled mapping between apps and domains)

UI changes

Before	After
!(Upload before screenshot)	(Upload after screenshot)

[cmonfortep]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Adds Feature Flag for Autofill Service #5567 👈 (View in Graphite)
• Autofill: Implement mapping for appPackages for autofill provider service #5508
• Autofill Service provider - showing suggestions on other apps - internal version #5561
• develop

This stack of pull requests is managed by Graphite. Learn more about stacking.

[CDRussell]

these should return false ?

[cmonfortep]

Discussed this offline. For those 2 values we've decided to take no action. They seem to be external to us, one even disabled by the user, so we should honor those disabled states and don't enable our service by our remote config.

New approach returns null for those states, and we don't update the value.