Like was done with channel imports, skip content import tasks if all the resources are already available. This is needed when the device is online because Kolibri will probe the channel data from the server regardless of whether content is needed or not. While working on this, I noticed that extra channel thumbnail downloads may be skipped if the channel was already present.
Sorry this is a bit big. I wanted to be sure there really wouldn't be any network requests if they weren't needed. That involved a bit of work with the test studio server so that it could respond to all the requests without having them stubbed out.
Like was done with channel imports, skip content import tasks if all the resources are already available. This is needed when the device is online because Kolibri will probe the channel data from the server regardless of whether content is needed or not. While working on this, I noticed that extra channel thumbnail downloads may be skipped if the channel was already present.
Sorry this is a bit big. I wanted to be sure there really wouldn't be any network requests if they weren't needed. That involved a bit of work with the test studio server so that it could respond to all the requests without having them stubbed out.
Fixes: #890