Update MobileSettings when user is removed from the store

Cherlyn pointed out an ongoing bug that should be fixed: If someone is removed from a store but that store is still in their cached "MobileSettings" we will allow them to log into it by default. Once they switch to another store they cannot get back, but until then they would have access. This can we fixed by validating the MobileSettings.Entity ID against the list of UserStores we are already pulling. In this case, we should re-pull the MobileSettings as if we did not have one at all.