Fix status bar window IME flags & layout

When bouncer was showing, but keyguard was occluded, staus bar
window couldn't receive input, and thus the IME window was placed
below the status bar window. In addition to that, fix the layout when
IME is showing up on the bouncer screen.

Bug: 19969474
Change-Id: I38d21647801b57608d49c3f525d4840e6ba58296