Left handed navbar: fix keyboard placement in immersive mode

when using immersive mode with left handed navbar in landscape the keyboard doesn't account for
the navbar appearing from the left and leaves an empty layer on the right, we need to use mStableLeft
so it takes its position accordingly.

Change-Id: I937e46661673b8560357afd4cbd7289bae87734f
SystemUI: Rework SearchPanelView calculations

Make isScreenLarge calculations match how the system calculates where to put the navigation
bar. This fixes certain cases where the quick launch buttons on the glowpad of the
navigation bar is improperly oriented.

Patch set 2: The eval should be greater OR EQUAL to 600, not just greater. Also cache result
into a boolean before returning it.

Patch set 3-4: Actually cache it this time.

Patch set 5-6: Make it final.

Change-Id: I5703578b4d49a6eeab100bb23167abd5cf9a326d