Simplify call history

It should be similar to the call history of a phone - instead of 3 separate entries, there should be one toast.
Currently, it looks like:
- Alice placed a call.
- Bob answered the call.
- Bob ended the call.
- Alice ended the call. *(sometimes when Alice gets Bob's hangup event later, after she ended it too)*

It should look like in the timeline (in a similar toast to the **Encryption enabled**, or verification):
**Incoming call (duration: 1 hour 2 min 5 sec)**
or
**Unanswered incoming call**
or
**Outgoing call (duration: 55 min 23 sec)**