fix(firestore): catch InterruptedException in FirestorePagingSource

[demolaf]

Fixes #2008.

FirestorePagingSource.loadSingle() blocks on Tasks.await(task) inside a Single.fromCallable. When Paging cancels an in-flight load, RxJava disposes the subscription, which interrupts the IO-scheduler thread mid-await, throwing InterruptedException. The source only caught ExecutionException, so the InterruptedException escaped the callable after the subscription was already disposed — RxJava couldn't deliver it downstream, so it surfaced as an UndeliverableException on the global handler and crashed the app.

DatabasePagingSource (RTDB paging) already catches InterruptedException and returns a LoadResult.Error instead of throwing; this applies the same fix to FirestorePagingSource.

Preview

• Currently working on a compilable sample for FUI-Android/firestore demos sample(app): add Firestore, Database & Storage demos to sample app #2406

untitled.webm

[gemini-code-assist]

Code Review

This pull request adds handling for InterruptedException in FirestorePagingSource.loadSingle to prevent undeliverable RxJava exceptions when interrupted while disposed, and includes a corresponding integration test. The review feedback suggests avoiding logging expected errors at the ERROR level in the library to prevent cluttering Logcat, and recommends saving and restoring the original RxJavaPlugins error handler in the test to avoid side effects on other tests.