Add back navigation ring customization.

Patchset 6 : Hide nav bar category on devices without nav bar

Change-Id: Iec29417ab65efc8df593508204b0981d5b193b74
Add back navigation bar customization.

Change-Id: I6431a611f3107fd1022df11362d1d2aa27b2f436
Add back hardware key settings.

Change-Id: I925fd9d9c02b86d8e93c8b9e25870433f7c20bde