Update comments on createAdjacentPageAnimForTaskLaunch

- Added comments to clarify pivot/drawBelowRecents is only needed if live tile isn't launching
- Otherwise TaskViewUtils.createRecentsWindowAnimator already take cares of the scrol offset and drawsBelowRecents.

Fix: 361744056
Test: manual
Flag: EXEMPT refactor
Change-Id: I10e7d72daaa13787a9fd19524f7f45c4b0d31642