Fit and finish for navbar camera affordance

- disable search gadget while interacting with camera
- clean up code that deals with warping to track both warp and swap views.
- fade camera and search icon when camera touched
- slide camera view on screen when camera is touched.
- fix fling of camera page to center in view when animation finishes.
- resolve stateful bug between edge swipe and camera button.

Bug 10332383

Change-Id: I8fc38148a01927bc7c228101308c3c4214113047