Add debugging information on PiP content overlay

Added the reason for creating the overlay. Updated
SwipePipToHomeAnimator constructor also due to the fact the source rect
hint from Builder class is never empty.

Bug: 330488822
Test: manually, follow the reproduce path
Flag: NA
Change-Id: Id98ce799d7c96fff3279c0df0fa49084a49d563a
1 file changed