Use a transition-drawable to crossfade between the gradient and
solid color backgrounds, avoiding custom onDraw.
Rename colors to their final names. Since both bars now receive the
gradient treatment, centralize in base BarTransitions.
Bug:10602521
Change-Id: Id094fa1767eabab88a3709d6026c23858c83fb5b
In LTR mode the navigation bar is:
- portrait (from left to right) : Back | Home | Recent Apps | Menu
- landscape (from top to bottom) : Menu | Back | Home | Recent Apps
This is kinda horizontally / vertically "pivoting +90 degrees" around the Recent Apps button.
In RTL mode, we had:
- portrait: Menu | Recent Apps | Home | Back
- landscape: Menu | Recent Apps | Home | Back
to make it similar to the LTR mode, we should have a rotation of -90 degrees around the Recent Apps button:
- landscape: Menu | Back | Home | Recent Apps
Change-Id: I9de511383b632ae8dea1396e9152109cc8a57c27
