Added clarification to docs on API manager session resumption behavior.
Added clarification to docs on API manager session resumption behavior.

InterfaceInc/Atlas-Messenger-iOS,layerhq/Atlas-Messenger-iOS,Eynaliyev/Atlas-Messenger-iOS,InterfaceInc/Atlas-Messenger-iOS,Eynaliyev/Atlas-Messenger-iOS,InterfaceInc/Atlas-Messenger-iOS,ropik/Atlas-Messenger-iOS,ropik/Atlas-Messenger-iOS,layerhq/Atlas-Messenger-iOS