* Remember whether sidebar is shown for calls when switching rooms
Stores the sidebar state per-room in LegacyCallHandler, along with other details about calls.
* Hide the Show/Hide Sidebar from the Picture-in-Picture preview
The toggle sidebar button currently does nothing in PIP mode, since PIP mode never shows a sidebar (even when the call is made fullscreen from the PIP preview)
* Add test for Show/Hide Sidebar feature
* Add more tests for LegacyCallView and LegacyCallViewForRoom
Also, fix issue where LegacyCallViewForRoom used roomId and not callId for checking for sidebar state