Fix #288 - Increase timeout for subscription test so filter storage is able to save

Flakiness in configures default subscriptions for en and configures default subscriptions for de is caused by filter storage sometimes taking to much time to save and causing ensureEverythingIsSaved() to hang for a long time.

As saving to filter storage is something that we can't control (it's core) - the only solution is to extend timeout (and do it for all browsers/ manifests as it happens randomly).