Screen sharing snapshots and back camera

Added

• Calls can now be started using the back camera instead of the front camera

Updated

• Call UI: A label is shown to the user notifying her when answering a call takes too long because of connectivity issue
• Call UI: Ending a call with low connectivity now dismisses the UI without waiting for the call to finish
• Snapshot: Snapshots can be now taken from screen sharing streams
• The SDK now uses the latest socket.io version

Fixes

• Now the call window rotation is fixed while sharing the in-app screen fixing a weird orientation issue in the stream sent to the remote
• Fixes ChannelViewController navigation bar layout bug occurring when the view controller is presented with modalPresentationStyle == .fullscreen
• Fixes a critical bug leading to the microphone not being muted after the user pressed the mute button with a specific timing while entering a room