Fix cache problems on apps

Since the store on apps is actually a transaction, the results are cached, so
if they get changed from outside (e.g. another station) they can display
wrong/old information.

Avoid that by doing a rollback everytime a refresh is done so that the cache
gets reloaded.

Change-Id: Ia60d637d3eeb38c1a73bca059d0c0bf4a5b2390a