Choose a matching record in split-screen stack

The split-screen primary stack should be chosen if activity is
launched that targets split-screen secondary, but a matching existing
instance is found on top of split-screen primary stack.

Bug: 77215248
Test: ActivityStackSupervisorTests#testSplitScreenPrimaryChosenWhenTopActivityLaunchedToSecondary
Change-Id: If3a47f793be2b9b84f822eacaa0befb28cc21d2e