[$125] Use valid loading indicator in `WalletStatementModal/index.tsx`

[mateuuszzzzz]

Details

As part of the loading indicator standardization, we are preparing to enable shouldUseGoBackButton by default in FullscreenLoadingIndicator. Before that, we need to migrate components where FullscreenLoadingIndicator is used alongside visible navigation to use ActivityIndicator instead, otherwise users would see two back controls (the header back button AND the Go Back button from the loader).

WalletStatementModal (web) is used by WalletStatementPage, which renders a ScreenWrapper with HeaderWithBackButton (statement title) and FullPageOfflineBlockingView. The modal renders an iframe that loads the statement page and uses {isLoading && <FullscreenLoadingIndicator />} as an overlay while the iframe loads. Important: The iframe MUST stay mounted while loading, the overlay pattern (loader on top of iframe) must be preserved, not a ternary that conditionally renders either the loader or the iframe. If the iframe is unmounted during loading, its onLoad callback never fires and isLoading would never become false.

Solution

Replace FullscreenLoadingIndicator with ActivityIndicator in src/components/WalletStatementModal/index.tsx. Keep the overlay pattern: the iframe must remain mounted at all times. The loading indicator should overlay it when isLoading is true. The replacement must be an ActivityIndicator wrapped in a parent View that provides the same layout and background styling as FullscreenLoadingIndicator. The loading state must be pixel-perfect identical after the change. Same background color, same opacity, same centered large spinner in the content area below the header.

Before making any changes, read the FullscreenLoadingIndicator component source to understand what styles it applies internally, and make sure the replacement reproduces them exactly. ActivityIndicator is a raw spinner with no layout or background styling, so it should not be used on its own as a fullscreen loading state. The codebase convention is to wrap it in a parent View that provides the layout and background styling.

Parent issue: #69850

Issue Owner

Current Issue Owner: @mateuuszzzzz

[melvin-bot]

⚠️ Could not update price automatically because there is no linked Upwork Job ID. The BZ team member will need to update the price manually in Upwork.

[melvin-bot]

This issue has not been updated in over 15 days. @Julesssss, @mateuuszzzzz eroding to Monthly issue.

P.S. Is everyone reading this sure this is really a near-term priority? Be brave: if you disagree, go ahead and close it out. If someone disagrees, they'll reopen it, and if they don't: one less thing to do!