Ensure VideoProvider is only set on ParcelableCalls for the default

InCallService (i.e. the Incall UI).

This ensures that only one InCallService ends up receiving the video
provider, and resolves an issue where multiple InCallServices would
register an video listener.

Bug: 17185020
Change-Id: I8aa021e091ba87788259c7eeda5e0cf408d3a964