Add edge-to-edge to WebView, onboarding and misc activity groups

[aibrahim-]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1212608036467427/task/1214047527401583?focus=true
Tech Design URL (if applicable): https://app.asana.com/1/137249556945/project/1212608036467427/task/1213993229311556?focus=true

Description

Roll out Android 15 edge-to-edge handling to web/onboarding/misc buckets, each gated behind a new sub-toggle of the existing edgeToEdge remote feature (default INTERNAL):

• webview: WebView, SettingsWebView, Subscriptions/Pir dashboards, EmailProtection in-context signup, GPM/Takeout import flows, PrivacyDashboard, Survey
• onboarding: SystemSearch, WidgetThemeConfiguration, AddWidgetInstructions
• misc: About, ChangeIcon, Bookmarks, BookmarkFolders, Downloads, GetDesktopBrowser, Windows, MacOs, Feedback, SubscriptionFeedback, RestoreSubscription, ChangePlan, Pir, EmailProtectionUnsupported

Each activity enables a transparent edge-to-edge window when its bucket is enabled and applies status-bar / navigation-bar / display-cutout / IME insets via EdgeToEdgeHandler.

Steps to test this PR

• Navigate to any of the Activities mentioned above.
• Make sure the edge-to-edge is enabled in gesture/3-button nav, and check the colors in light/dark themes.
• Gesture nav should be transparent.
• Cutout should always be dark in landscape regardless of light/dark themes.
• Try on different devices/API levels.
• This PR concluded all user facing activities, so should feel free to test any activity.

UI changes

Screenshots selection: https://app.asana.com/1/137249556945/project/1212608036467427/task/1216217807064104?focus=true

---

Note

Medium Risk
Wide UI-only rollout behind remote toggles, but touches many entry points (system search, browser scrims, nested scroll/inset edge cases) where regressions would be visible rather than silent.

Overview
Extends the gated edge-to-edge rollout with four new remote sub-toggles (webview, onboarding, misc, bottomSheets) and wires many activities, VPN/autofill flows, and bottom sheets to respect them.

Infrastructure: EdgeToEdgeHandler gains scrollable nav-bar insets (applyScrollableNavigationBarInsets), combined horizontal + nav margin insets, full applySystemBarInsets, optional status-bar scrims (installScrim = false on browser/custom tab), and View.applyBottomSystemBarInsetPadding() for Material bottom-sheet windows. Shared .EdgeToEdge bottom-sheet themes disable Material bottom auto-padding to avoid double padding. Splash uses Theme.DuckDuckGo.SplashScreen.EdgeToEdge (landscape API 27+ sets cutout mode never for letterboxing).

Activities: When a bucket is on, screens call enableTransparentEdgeToEdge() and apply tailored insets—e.g. SystemSearch (top vs bottom omnibar), WebView hosts wrapped in containers, fixed bottom CTAs padded above the nav bar (drawBehindGestureNav = false), lists/recyclers using scrollable nav insets. VPN activity feed only insets when not nested in a parent scroller.

Bottom sheets: Fragments pick plain vs .EdgeToEdge themes via EdgeToEdgeBucket.BOTTOM_SHEETS and pad dialog roots with applyBottomSystemBarInsetPadding().

^{Reviewed by Cursor Bugbot for commit b09e894. Bugbot is set up for automated code reviews on this repo. Configure here.}

[mikescamell]

@aibrahim- I'm seeing differences between the status bar for the settings screen in dark mode. Light mode seems fine. Edit: Also seems to apply to most sub-settings screens.

Prod	Branch

[mikescamell]

@aibrahim- We're also a little tight with padding at the bottom of the PrivacyDashboardHybridActivity in gesture mode compared to prod. Same applies when this is in landscape.

Prod	Branch

[mikescamell]

@aibrahim- Did we do anything for bottom sheets already? For instance I noticed the Import passwords from Google bottomsheet has a scrim for the gesture navigation bar, where I would have expected it to be transparent like the Passwords & Autofill screen

[mikescamell]

@aibrahim- In phone landscape, on the Passwords & Autofill screen, there's not enough content padding between the last item in the list and the gesture bar

Prod	Branch

[aibrahim-]

re modals/bottom-sheets, they were originally planned for next week, but I can do it now to avoid an extra ship-review: https://app.asana.com/1/137249556945/project/1212608036467427/task/1214047527401585?focus=true

[mikescamell]

@aibrahim- Seems we have a couple of issues with navigation on Bookmarks screen, this was a Pixel 4a, API 33

1. In gesture mode it bleeds into the bottom bookmark item if it fills the screen

2. In 3 button nav mode there's no scrim, which makes it hard to see the button, and doesn't match our screens elsewhere

[mikescamell]

@aibrahim- Seems we have a couple of issues with navigation on Bookmarks screen, this was a Pixel 4a, API 33

1. In gesture mode it bleeds into the bottom bookmark item if it fills the screen

2. In 3 button nav mode there's no scrim, which makes it hard to see the button, and doesn't match our screens elsewhere

The solution for this would probably solve the same problem in the BookmarkFoldersActivity where the gesture bar bleeds into the last item Edit: And it also has the 3 button nav issue as well where it has no scrim

[mikescamell]

@aibrahim- Downloads screen also has the last item being overlayed by the gesture bar

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 78553cf. Configure here.}