`getFileFromCache` future does not resolve sometimes on android

Hey together,

there is an issue with the flutter_cache_manager which is only happening sometimes on android. At this point we are not sure under wich circumstances, but most of the times when something changes on Android (e.g. Application switching, Updating the App version)

My code looks like this:
```dart
logMessage(
'Loading file from cache...',
extras: {'File': url},
);
var file = await _cacheManager.getFileFromCache(url);

if (file == null) {
logMessage(
'File not in cache. Marked for retrieval.',
extras: {'File': url},
);
futures.add(_repository.retrieveAsset(url)
..then((file) async {
logMessage(
'File successfully retrieved. Caching...',
extras: {'File': url},
);
await _cacheManager.putFile(url, file);
logMessage(
'Successfully cached file.',
extras: {'File': url},
);
}));
} else {
logMessage(
'Found file in cache.',
extras: {'File': url},
);
}
```
The logs are only going until `Loading file from cache...`, after that the class is never returning any logs. So it is likely that the error is in `var file = await _cacheManager.getFileFromCache(url);` as the future never resolves. Moreover the problem is not reproduceable on any device as long as the debugger is attached. At this point I am not sure what to do anymore. Maybe you have any ideas?

Start at getFileFromCache(url) and investigate its future completion on Android when the application is switched or updated, with the debugger detached. The report provides no named files or tests, so first establish a reproducible lifecycle scenario and trace where the future stops completing. Done means the cache lookup resolves or reports an error reliably in that scenario.

Scritto dal modello di indicizzazione a partire dal testo della issue.