Consider launching task's position on screen in pivot calculation

- Instead of using RecentsViewScroll, put task's position offset versus current scroll as TaskRect calculation, so it's considered when calculating for putting task to full screen
- Revert back RecentsViewScroll to apply before RecentsViewScale
- Added new property in PagedOrientationHandler to apply both primary/secondary param without clearing the other, and renamed an existing method

Fix: 206972618
Test: Quick switching
Test: Launch task from grid, launch side task from carousel overview
Change-Id: I5977975ed1e930ad70b81d83513d8f3a00c0aed4