IMS-VT: Moving upgradeVideoRequest handling to InCallPresenter

When user pressed back key InCallActviity will be destroyed and
corresponding listeners in VideoCallPresenter will be removed.
Due to this we are unable to process the upgrade request.

Moving handling of upgrade Video Call request handling from
VideoCallPresenter to InCallPresenter as InCallPresenter will be
available even InCallActivity is destroyed.

Bug: 27130345
Change-Id: Idbd3348cea9d712c8391319d091642d1fd60964f