IMS-VT: Fix issue of screen timing out after orientation change

During activity recreation on orientation change, InCallActivity
instance is not updated in InCallPresenter when screen
timeout is being disabled. To fix this, enable/disable screen
timeout using activity instance retrieved from VideoCallFragment.

Change-Id: I6b816482a8e981a8dae11799a7b7e5880476a6ea
CRs-Fixed: 1032198
3 files changed