[native] add button to test creating olm session with own devices

Summary:
Code for testing creating olm sessions. In future this will be triggered automatically, but for now when devices are not yet logged into Identity this is only for testing purposes.

Depends on D10381

Test Plan: Click button and check results in logs

Reviewers: marcin, varun, michal

Reviewed By: michal

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10382