Support entering split screen with a shortcut and an intent

Starting a split pair by indicating (shortcut|shortcut) or
(shortcut|intent) was not properly supported, update to leverage
startIntens flow to handle shortcut info when starting a split pair.

Fix: 265919000
Test: repro steps of the bug
Change-Id: I9afcd6f3cdfb5530c1b440a9c0ade8c9952a5fff