Apply the current system window insets to launcher preview

For wallpaper picker, the position of app icon on the wallpaper preview would match to the launcher after applying the wallpaper.

Wallpaper picker: https://screenshot.googleplex.com/JZazpgZLgzacZMZ.png
Launcher: https://screenshot.googleplex.com/9uTTQwdmcnFZ7Vi.png
Gesture mode: https://screenshot.googleplex.com/3YaKbBerYgtHBFb.png
3-button mode: https://screenshot.googleplex.com/7sA5nE3GmbuKf62.png

Fixes: 188539072
Test: Manually
Change-Id: I553000e6ae646207eb94fa33e97d00a3990043c8
2 files changed