Calculate wallpaper offset with associated display info

If the wallpaper has applied fixed rotation transform, it should
use the local display info. This change centralizes the access of
display info to WallpaperController#updateWallpaperOffset, so the
caller won't pass mismatched display size.

Bug: 152977308
Test: atest DisplayContentTests#testApplyTopFixedRotationTransform
Change-Id: If167e82c71d0f039691155a2aad28c2b78c683de