Report pending change to wallpaper when being visible

Configuration change will make mLastConfigReportedToClient true.
But if the window is invisible, updateResizingWindowIfNeeded may
be skipped by isGoneForLayout. So if it becomes visible later,
request a traversal to dispatch the change and then the client
window (wallpaper) can redraw with the latest state.

Fix: 261988495
Test: WallpaperControllerTests#testWallpaperReportConfigChange
Change-Id: I7f43811ac6d0582e9b904ad3cad7d98e1605877a