Fix issue #5283365: Rotating the device to portrait mode, hides the keyboard partly

PhoneWindowManager now takes full responsibility for deciding where the
navigation bar goes.  This gets rid of a bunch of race conditions with
determining layout while the nav bar is moving itself at the same time
the window manager is computing a new configuration.

Note that this breaks the "nav bar on left" option.  The current nav
bar code could also be cleaned up some more to completely drive its
behavior based on onSizeChanged() happening during relayout.

Change-Id: I1651d74c3464ba0d588aab3049e099c78420146a