Allow recent apps to be launched with split screen pair from MediaProjectionAppSelector

Updating the logic so that when selecting a recent app to partial screenshare, if it is currently part of a split screen pair, the pair will be launched together

Bug: 320449039
Flag: ACONFIG com.android.systemui.pss_app_selector_recents_split_screeen DISABLED
Test: Manual testing
Test: atest ShellRecentTaskListProviderTest
Test: atest MediaProjectionAppSelectorControllerTest
Test: atest MediaProjectionRecentsViewControllerTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:558bf873fa3683962e0002bc5061032be56d3bb4)
Merged-In: Iff49ff89ea2367187f8ba34bad6730a1bb6f3738
Change-Id: Iff49ff89ea2367187f8ba34bad6730a1bb6f3738