Redirect launching app from PiP on another display to PipExpandHandler.

This allows the task that went into PiP to be launched in the default
windowing mode of the other display.

Video: http://recall/-/eJKbR8nWsDdR7iqlcyUtXB/bC6SS5oP2HCertOS940IOr

Flag: com.android.window.flags.enable_cross_displays_pip_task_launch
Fixes: 424569682
Test: atest PipExpandHandlerTest
Test: atest WMShellFlickerServicePipTests:ExitPipToAppViaIntentTest
Change-Id: Iaf0770902e232fb8ccc006f371f4e32e7dcf0f27