file is downloaded by eTag condition but not updated in cache

## 🐛 Bug Report

1. Load a file image with max-age = 5 second (there is overriden value of 0 seconds with 7 days - which is not good actually).
2. Replace file on server with new one
3. Reload image

Actual result:
it is visible that code 200 is coming from file download, file is actually downloaded, but memory cache not updated, old file is added to stream produced by getFileStream(url) method (the last one, the first one is from memory cache which is OK).
App restart helps to see new file (code 304 is reported by server, file is not actually downloaded).

Start at the getFileStream(url) entry point and trace the path taken after a 200 response from the server. Check how the downloaded file updates memory cache, then verify that reloading after replacing the server file produces the new content in the stream without an app restart.

Vom Indexierungsmodell aus dem Issue-Text verfasst.