Fix notification shade not expanding from right side after unfold

The width of mKeyguardStatusBar is not adjusted when unfolding. It is only adjusted once the shade gets expanded the first time. Therefore we need to query the window width and use that instead for the back bypass check.

Bug: 309628369
Flag: LEGACY WM_SHADE_ANIMATE_BACK_GESTURE DISABLED
Test: Manual, i.e. testing shade expansion behaviour after unfolding
Change-Id: I4c8453fb6bd2357f9c975435e0806b33a8375164