Open the performance-optimized paywall URLs when the flag is on - #9757

Task/Issue URL: https://app.asana.com/1/137249556945/project/1217319487385906/task/1217750626830941?focus=true
Tech Design URL (if applicable):
API Proposals URL(s) (if applicable): None

Description

Opens the performance-optimized paywall page when the performanceOptimizedPaywalls flag is on, so the front end can test the faster entry points on Android.

• The paths come from the flag settings, so they can change in remote config without an app release Add performanceOptimizedPaywalls feature flag (off by default) privacy-configuration#5809
• The URL carries trial=true or trial=false from free trial eligibility, and pir=false when PIR is not part of the offer, so the page renders without asking the app what the user is being offered.
• Params the app already sets, such as origin, are carried onto the new path unchanged.
• With the flag off, the old URL is loaded and nothing changes.

Steps to test this PR

• Apply the pinned staging patch from https://app.asana.com/1/137249556945/project/1209991789468715/task/1210448620621729?focus=true and install the internal debug build on a device with Google Play.
• Launch the app once with network and confirm the remote config has landed: Settings > Internal Features > Privacy Config Internal Settings, check "Latest Loaded Date" is today. The paths come from the config, not from the app, and they ship in Add performanceOptimizedPaywalls feature flag (off by default) privacy-configuration#5809.
• Settings > Internal Features > Feature Flag Inventory, search performanceOptimizedPaywalls, turn it on.
• Filter logcat on SubscriptionsWebViewActivity. It logs the URL every time the paywall opens. Every check below just reads that line.
• Optional, to see the page render: take the current front end tunnel URL from https://app.asana.com/1/137249556945/task/1216295712277568, put it in Settings > Internal Features > Subscriptions Dev Settings > "Enter the base URL for subscriptions", and Save. The tunnel is temporary.

VPN paywall

• Open from Settings > Privacy Pro. URL should be /subscriptions/new/mobile/vpn.

Duck.ai paywall

• Open from a Duck.ai entry point. URL should be /subscriptions/new/mobile/duckai, with no featurePage in the query.

Query params

• Trial eligible account: trial=true. Account that already used a trial: trial=false.
• Region without PIR: pir=false present. Region with PIR: no pir param.
• Open from app settings: origin=funnel_appsettings_android and environment=staging both survive onto the new path.

Flag off

• Turn performanceOptimizedPaywalls off, open the paywall. URL should be /subscriptions with no trial or pir, and the old page loads.

Fallback

• Force stop the app, reopen, go to the paywall before Google Play has loaded products. Old URL loads, no error page, no crash.

UX changes