[Bug] Remove functions when deleted by app, even if the app function service info is still present.

Scenarios reported by photos team:

- When all app function implementations are removed keeping the SDK still in app the AppSearch preserves the removed functions instead of deleting them.

- System apps like Photos when the updates containing app functions is uninstalled, since the app package itself isn't/can't be removed the functions are not removed.

Change-Id: Ia1004de817131a226bc932bbc8667ec0136c9f5c
Flag: EXEMPT Small bug fix
Test: atest AppsIndexerTests
Bug: 380729091