Handle fullscreen mode toggle when tapping contact photo.

1. Moved the fullscreen mode state tracking and logic from
VideoCallPresenter to InCallPresenter (since it is more to do with the
entire InCall UI rather than just the video presenter).
2. Added click handler for the contact card to toggle fullscreen video
mode.

Bug: 20912417
Change-Id: If1656365f7fcfcee5a902c7f5d5d2862edee1661