audio-studio/android: cover the foreground-service lifecycle with an instrumented test #478

Follow-up from #477, suggested during its review.

ForegroundServiceLifecycleTest guards the #474 fix with source assertions: a truth table over the extracted rules, plus checks that each call site is wired to them. That was mutation-tested against 20+ regression shapes and catches every one, but it has a structural limit the reviewer named plainly:

Source parsing cannot prevent every future weakening [...] A behavior-level instrumented test would be the stronger follow-up.

The specific loophole left open, judged not worth blocking the merge: narrowing if (ownedService) with && recordingConfig.keepAwake passes the containment-based guard assertions and could leak a notification-only service.

What an instrumented test would assert

Run on a device, and check the service rather than the source:

1. Record with the default config (keepAwake=true, showNotification=false), stop, assert no ServiceRecord remains
2. Same with showNotification=true
3. Record, stop, prepare a successor, assert no service is stranded
4. Record with both flags false, assert no service was started

All four are exactly what was verified by hand on a Pixel 6a for #477 via dumpsys activity services. Automating them replaces source-shape assertions with behavioural ones.

Blocked by

#475 — the instrumentation harness cannot run at all today for sherpa-onnx.rn. Whether audio-studio's androidTest suite runs is worth checking separately before this is picked up.