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
Merge remote-tracking branch 'cyan/cm-11.0' into cm-11.0